Imagine if you had never seen a vid of trials ? all you would know how to do and whats possable is what you have seen everyone you ride with.
It deffo helps
But if you sit eating burgers and watching vids and not riding or trying the stuff you see on the vids you wont get good! see it try it
Update
Just got a effect in to try out
looks nice but bars are 25 inch wide and gear is to hard and skips because chain is only round about 5 of the 13 t cog !
I think with wider bars and 14t/15t cog the bike would be much better. The rear hub is a bit gappy but quite strong also ive noticed a strange mount on the disc side i think it will become a bolt on disc guard !
I got into it about a year ago and got a 1999 beta techno 250 for £600.
It was really good but a bit snappy hard to control at very slow speeds .
I now have a 2005 beta rev 3 its much smoother and lighter and turning iS much tighter.
I would say get the best bike you can with your money but make sure you have some left over for repairing it!
I fell off lots when i started broke levers and gear lever almost every time i went out because i was going nuts up hills far to steep.
Beta = well made BUT have sticky clutch problem but its a easy fix
GASGAS = not well made but ride very nice
Scorpa = very good and has yam engine
Montesa = well made but out of date and has very good honda engine
Thats what i would stick with
250 if your 16 or older for local comps a 125 will do most of it but a 250 is best all rounder