but im sure that these woods wouldent be owned. its very smallYou'll find you can't just go digging up woods, and you could end up in lots of trouble with a land owner. Riding an MTB you also have to be aware of not 'hissing' off landowners and other users as it can only lead to bans on access. We want access rights opening up. Unfortunately, if you've not got permission, a land owner is within their rights to pull down any features you make. If using and cheeky trails, bear this in mind.
I would suggest you spend a bit of time googling and reading about making jumps etc, and check out some articles on-line rather than expecting a 'spoon fed' response to everything.
Also, google changing punctures, you've probably paid well over the odds for a replacement tube and fitting. Slime in tubes - no point.