Why do I only have pip3 but no pip?
If you had python 2.x and then installed python3, your pip will be pointing to pip3. you can verify that by typing pip --version which would be the same as pip3 --version.

On your system, you have now pip, pip2 and pip3.

If you want you can change pip to point to pip2 instead of pip3.

you can either add the alias to your ~/.bashrc

 alias pip=pip3


or add to your $PATH symlink named pip pointing to pip3 binary