First, you want to make sure that your username is setup for posting in the community. You can do this by going to your "Profile/Settings" area (which is the 3 line button next to the Community tab) and then going to "My Settings" and creating a username and uploading an avatar picture. (https://www.energyup.co/settings/edit)
Once you have created and saved your username, to commentT in our "Community" make sure to click on the "Community" tab and then click on "Forums" or "Trending Topics". From there you can click on the group you would like to participate in such as "Daily Missions", "General Discussions", "Energy Up Radio Shows", etc. Once you have clicked on the group you want to participate in then you can click on the thread topic you would like to comment in or add a reply to. This can be a certain day posted, or topic name someone has created, etc.
When you have clicked on the thread topic you will see "Reply", "Edit", or "Delete" towards the bottom of the person's comment. Click on the "REPLY" button to the person you would like to reply to and you will be able to comment or "like" their comment.
If you want to post your own new topic you can do so by clicking on the "General Discussions" and then once you have do so click on "New Topic" and you can start a new discussion in the community.
Please let me know if I can help you with anything else.
Good luck with your workouts!