l wanna mount on a horse

Go to horse riding lessons they will teach you the safest way to get on a horse. Just do not approach them directly from behind as they may kick.
Obviously there are no guarantees with any animal but the horses at riding schools have been broken in and are used to being ridden so you should be fine.
Just remember to always wear a riding hat.

Wrong section, but l will answer it

I'd suggest a calm, old horse for a beginner. Depending on how big u are/how bigthe horse isyou can either get on a mounting block (just a big thing to stand on), u can climb up the side of the coral fence & then mount, or the way to get up is if u were on the right side of the horse, you'd throw ur right foot into the stirrup, grab the pommel & hoist yourself up. If you're riding English style (which is unlikely as a beginner) you'd do the same thing, except there is no pommel, so u can grab the front of the saddle or the horse is neck.

When you're mounting make sure the horse knows where u are, u do not want to startle them & get kicked or stepped on. It is really painful.

Good luck!