Bunnies are usually very skeptical in general and given your bun’s history, this will be even more so, i’m guessing. Best thing to let him know you aren’t scary is to how him. This will take time. Make sure you are taking it slow and going at his pace. Don’t force anything and take his lead. Now that he is in a new home, let him have space. I’m assuming you have some type of cage or “home” set up for him? Don’t disturb him while he is in here, don’t force him out, and naturally let his curiosity come out. This way it can serve as a safe zone. When you can, spend time around his area but don’t intrude. Sit outside of his area and do your regular routine (e.g., read book, go online, watch TV, etc.). Naturally, he will see you as non threatening as time goes but and eventually he will come around as his curiosity will get the best of him. Don’t try to pick him up and don’t chase him. You can also feed him treats by hand but don’t become upset if he doesn’t respond at first or if he just snatches the treat and eats it away from you. Have patience, good luck!