I do a little free running.
Best thing i can do is run up about a 5 foot wall or tree and grab onto something before i freak out and slip lol

There are multiple free alternatives to Minecraft.
I don't think I will say one though cause it's probably illegal but PM me and I might share some info

No. No, that wasn't rofl.

You are asking a large group of gamers about how to do a very difficult and strenuous physical activity. My suggestion would be to find someone who actually does it. Assassin's Creed does not teach you (had a friend put his foot through the wall, which was funny, trying to be Altaiir)