Hi, if I haven't said it before, welcome to FishLore!

I don't know that much about Angels, but you could definatly have one Angel. You can try two but there may be aggression issues.
Someone who knows more about them can advise you further.
Clown Loaches get much too big for a 36g tank.
It's recommended they have at least 75g.
I was really surprised the first time I saw a full gown Clown Loach, those babies are big!