Open up your app to the home screen and select the Squads tab. 

You will be able to scroll through your Squads and see if there is any activity in your Squad feeds. Select either Activity, Messages, Members or PR's to be taken to that specific feed.

Taking a look into the PR's in the "r/CrossFit" Squad. I can easily throw a thumbs up, comment or even select the workout to give it a go myself.