What could I concretely do to work on keeping no records of wrongs and trust people?

Start by trusting people in the small things.

Explanation:

Forgiveness is a very hard thing to do. People have a lot of pride and quite frankly forgiving someone means giving up one's pride.

From experience, moving on from someone else's mistakes takes time and effort. Starting small like allowing that person to be in your life for the small things is already a big step. Even if it is small talk, anything is a step closer to finally opening up your comfort zone box and trusting another person again.