Configuration of the Maven

Question

I created a project Maven (NOTE: It is the first time I am touching this technology), but he is making this mistake. This plugin what message is talking about I need to install it? How do?

Another thing, when I go to propriedades do projeto >> Project faces and click on dynamic web module 3.1 he asks for the version of java 1.7. Is that right? In my opinion it should point to the Java 1.8, since the technologies I’m using are more current.

My grief is with these settings:
- Maven 3.3
- JDK 1.8
- Tomcat 8.0.23

Could someone help me?

EDITION: this is my pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.hellemos</groupId>
    <artifactId>Financeiro</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>  
</project>