My manny is just getting settled and and just started eating the other day (after not eating for first week). I' tried silversides for a few days and he didn't look at him but threw a piece of shrimp in and he took a few bites.
Best bet is to just find out what they were feeding him at the pet store and start with that (and don't let anything sit in the tank for too long. If he doesn't eat it, take it out after an hour). As for him being scared, my elong is still very shy and hides when i walk in (after hearing that they are the most aggressive p out there). I asked a lot of people and did a lot of research but it's really just a waiting game on when they come out of their shell. Once they feel comfortable and start to eat (and know you have food) they will chase you.
Just do everything you can to make him comfortable (hiding places, low lighting, clean water) and i'm sure he'll turn out great.
