Congrats! The first time is always exciting. :)
However, it does look like your friend's saddle doesn't fit. Looks like it is sitting directly on his withers, which is a good excuse for any horse, let alone a greenie, to dump you. ;) I wouldn't use that saddle again.
Not trying to be a downer here, but I doubt you want to intentionally hurt your horse and potentially sour him to having a saddle on. Good luck!
Proud owner of ~Mana: 6yo Arabian gelding~Pearl 13yo Arabian~Danzer 14yo Arabian mare~ Tiny mini filly