Figure positioning on Latex page

Question

When I put a figure on Latex, the figure leaves the place where I put it, it goes to the middle document or end of it. Everything gets messy. How can I fix this?

I do:

\begin{figure}[ht]
    \centering
    \includegraphics[width=8cm]{Nome do arquivo}
    \label{figura01}
\end{figure}

Decreasing the figure it until it "fits", but there are figures that I NEED to be big, otherwise you can’t see. Sometimes even decreasing the figure fits.