If you plan on riding him don't give him carrots,apples or any treats.
It will make him fatter and hyper and out of control.
I really advise you not to ride him, I'd even be weary of riding him and I'll hop on anything and am experienced.

Well most food horses eat is "dead" unless they are on pasture, and pasture is actually NOT always good for horses.
Ther person who owns my barn had to put a horse muzzle on her min pony because he was eating too much of the grass and formed some kind of problem (I forget what it was) but it's deffinatly not good if you have a horse that just eats and eats.

Sounds like they should find him another home.
Why? He's being taken care of and just put to pasture. There's is nothing wrong with that and most retired horses or horses who can't be ridden are put to pasture.

I will not try to put a bridal or sadle on him without help from my boyfriend (He has lots of horse experience, he used to break them as a carrier).
Sounds like you have some good help then. What did he break them for?

You have lots of great advice here