bbPress.org

As said above:
For your plugins, you should activate them from your ‘Admin panels > Plugins > Installed Plugins’ and then you can start tuning the options (in most cases under ‘Admin panels > Settings’ or ‘Admin panels > Tools’.
If they do not work, then you need to ask on the forums of those plugins.

For the avatars, you can start reading here: https://codex.bbpress.org/getting-started/faq/user-avatars/

Pascal.