This app is what got me back into lifting
I haven’t done lifting in years, in part because I had an awful time deciding what lifts to do on a regular basis. This app gives suggestions on what lifts to perform to hit certain muscle groups based on what you haven’t worked recently. It even updates after every lift; if it recommends working biceps, and then you add a bicep lift, it will update suggestions in real-time to focus on the next muscle group.
Highly recommend giving it a try!