This is for what to do after you put your name in to volunteer:
Any training that you will get will probably focus on your legal obligation and what is expected of you as an observer. There will not be enough time to train you on everything to watch out for. Even though the campaign has not gotten back to you yet, assume they will use you. Start your training now.
Secondly, become familiar with your state’s laws on recounts:
Pennsylvania: Look at Chapter 14 especially Article XVII
Michigan: Look at Chapter XXXIII
There are many videos on things to look for: