Blunderland: A place to find joy in learning from mistakes (ELO 500 and lower)

I would like to create a place for true beginners to learn how to learn from mistakes, so since it's the holiday season for many, I thought "Blunderland" might fit the theme.

My idea:  

1.  Post a single snapshot in a game.

2.  Describe what you feel is going well

3.  Describe what you think isn't

4.  Ask a question, if needed, to see if folks with more experience might respond

So, here is my first go of this.

1.  Here's my pic:

2.   It took 74 games for me to realize that I had no "Theory of Mind" for my opponents play.  Since considering this more in the last couple of days, my blunders have gone down.  I also think my position is relatively strong in this game, despite only being up one piece.  

3.  When I reviewed the game, I 100% did not see the free bishop, but even if I did, as a newbie, I wouldn't know whether to risk losing my position to take it.  I liked that my bishop and queen are lined up on the diagonal directed toward the opponents king, I like that my pieces are fairly protected, and  I like dark squared bishop's position.

Question:  When you have a strategy, as rudimentary as this one is for me, when should you leave a strategic position to take a free piece?   If you wanted to play a positional game, what would you do in this situation?

As a 900 elo player I would take the free piece and then return my piece where it was to keep the positional advantage.

Having a good position is...well, good. But if your opponent leaves a piece open to capture, then by all means you should take it, as long as it's not a trap. And in this case, it's just a blunder.

Black would have likely played Rb8 afterward; just move your queen out of the way (Qa7). Sure, they can get their rook to the seventh rank, but what's it gonna do there? Everything is guarded. After Rab1, black is better off just trading the rook off. This is because if they play Rc2 in an attempt to keep their rook where it is, Bxe7 leaves black trapped in a rare middlegame zugzwang; no matter how they recaptures your bishop, they're going to lose their other bishop at least, or face an unavoidable bank-rank mate at worst.

Also, after Rb8, playing Bxe7 immediately is not a terrible move either. This move offers to trade queens, and the position will be simplified if black accepts; since white is the one with an extra piece, that's bad news for black.