Positioning <p> on one side and img on the other

Question

I’m not getting my position <p> left and mine <img> right, and even worse the first label of my form rises above my header, how do I position ?

<div class="container">
<div class="col-12 col-md-12">
  <header>
    <div class="row" id="topo">
      <p id="description">Preencha o formulário abaixo para falar diretamente com nossa DICOL.</p>
      <img src="assets/img/logo-ALO-Dicol.png" alt="img" id="logotop"/>
    </div>
  </header>
  <div>
    <form class="form" id="formalodicol">
    <div class="form-group">
      <label for="nome">Nome(Opcional):</label>
      <input id="nome" name="nome" class="form-control" type="text" placeholder="Seu nome"/>
    </div>
    <div class="form-group">
      <label for="email">E-mail(Opcional):</label>
      <input id="email" name="email" class="form-control" type="email" placeholder="Seu e-mail"/>
    </div>
    <div class="form-group">
      <label for="Assunto">Assunto:*</label>
      <input id="assunto" name="assunto" class="form-control" type="text" placeholder="Assunto" required/>
    </div>
    <div class="form-group">
      <label for="mensagem">Mensagem:*</label>
      <span><textarea maxlength="2000" id="mensagem" name="mensagem" placeholder="Sua mensagem aqui..." required></textarea></span>
    </div>
    <div class="form-group">
      <button id="submit" type="submit" class="btn btn-primary">Enviar</button>
    </div>
    <br>
    <div id="resp"></div>
  </form>
  </div>
  <footer>
    <div class="row" id="rodape">
      <p id="developed">© 2019 developed by <img src="assets/img/logoGETEC.png" alt="img"/></p>
    </div> 
  </footer>
</div>

CSS:

body{
 font-family:'Helvetica Neue', 'Helvetica', 'Arial';
 background-image: linear-gradient(#74b49b, #a7d7c5);
 color: #f4f9f4;
}
#rodape{
    position: static;
    display: block;
    margin-top: 15px;
    text-align: center;
    bottom: 0;
}
#topo{
    display: flex;
    float: right;
    margin-top: 3%;
    margin-bottom: 3%; 
}
#logotop{
    max-width: 350px; 
    max-height: 120px;
    width: auto;
    height: auto;
    float: right;
}
h3{
    margin-top: 30px;

}
#description{
    color: white;
    font-weight: bold;
}

#developed{
    font-weight: none;
    color: grey;
}

.error{
    color:red
}

.form-group{
    display:block;
    margin-bottom:1rem;
    width:100%
}
.form-group input,.form-group textarea,.form-group button{
    display:block;
    width:100%;
    margin:.25rem 0;
    padding:.7rem .95rem;
    border:none;
    border-radius:.2rem;
    font-size:16px;
    outline:none;
    transition:all linear 200ms;
}
.form-group textarea{
    resize:vertical;
    height:180px
}
.form-group label{
    display:block;
    margin-bottom:.5rem;
}
.form-group button{
    margin-top: 30px;
    background-color: rgb(0,107,62)!important;
    color: white!important;
}

Answer 1

Hello. You are wearing display: flex; in the #topo, so you’re not able to position with float. Your flexbox is in column mode, so all elements will be in a single column. What you can do is add flex-direction: row; in the #topo so that the items are all in one row and then use justify-content: space-between; so that items have as much space as possible between them, that is, the description will be as far left as possible and then as far right as possible.

Take a look over flexbox in that guide: https://origamid.com/projetos/flexbox-guia-completo/

Follow the code modified and working:

body{
 font-family:'Helvetica Neue', 'Helvetica', 'Arial';
 background-image: linear-gradient(#74b49b, #a7d7c5);
 color: #f4f9f4;
}
#rodape{
  position: static;
  display: block;
  margin-top: 15px;
  text-align: center;
  bottom: 0;
}
#topo{
  margin-top: 3%;
  margin-bottom: 3%;
  display: flex;
  flex-direction: row;
  justify-content: space-between;
}

#logotop{
  max-width: 350px; 
  max-height: 120px;
  display: inline;
}

h3{
  margin-top: 30px;

}
#description{
  color: white;
  font-weight: bold;
  margin: 0;
}

#developed{
  font-weight: none;
  color: grey;
}

.error{
  color:red
}

.form-group{
  display:block;
  margin-bottom:1rem;
  width:100%
}
.form-group input,.form-group textarea,.form-group button{
  display:block;
  width:100%;
  margin:.25rem 0;
  padding:.7rem .95rem;
  border:none;
  border-radius:.2rem;
  font-size:16px;
  outline:none;
  transition:all linear 200ms;
}
.form-group textarea{
  resize:vertical;
  height:180px
}
.form-group label{
  display:block;
  margin-bottom:.5rem;
}
.form-group button{
  margin-top: 30px;
  background-color: rgb(0,107,62)!important;
  color: white!important;
}

#formalodicol{
  clear: both;
}

<div class="container">
<div class="col-12 col-md-12">
  <header>
    <div class="row" id="topo">
      <p id="description">Preencha o formulário abaixo para falar diretamente com nossa DICOL. </p>
      <img src="assets/img/logo-ALO-Dicol.png" alt="img" id="logotop"/>
    </div>
  </header>
  <div>
    <form class="form" id="formalodicol">
      <div class="form-group">
        <label for="nome">Nome(Opcional):</label>
        <input id="nome" name="nome" class="form-control" type="text" placeholder="Seu nome"/>
      </div>
      <div class="form-group">
        <label for="email">E-mail(Opcional):</label>
        <input id="email" name="email" class="form-control" type="email" placeholder="Seu e-mail"/>
      </div>
      <div class="form-group">
        <label for="Assunto">Assunto:*</label>
        <input id="assunto" name="assunto" class="form-control" type="text" placeholder="Assunto" required/>
      </div>
      <div class="form-group">
        <label for="mensagem">Mensagem:*</label>
        <span><textarea maxlength="2000" id="mensagem" name="mensagem" placeholder="Sua mensagem aqui..." required></textarea></span>
      </div>
      <div class="form-group">
        <button id="submit" type="submit" class="btn btn-primary">Enviar</button>
      </div>
      <br>
      <div id="resp"></div>
    </form>
  </div>
  <footer>
    <div class="row" id="rodape">
      <p id="developed">© 2019 developed by <img src="assets/img/logoGETEC.png" alt="img"/></p>
    </div> 
  </footer>
</div>

I hope I’ve helped.