1.the tuning can adjust by ownself?
yes but u need timing light and vacuum gauge and knowledge on how to do. cant explain here as there is too much kungfu need to show den onli can explain

2.wad is timing advance off??
thats how early your sparkplug fires before your piston reaches TDC (top dead center) can adjust yourself but need timing light. adjusted by changing the angle of the distribution cap

3.tappet?? i dunno wad is that..
thats the things that push open your valves. all u need is a feeler gauge and a spanner and a screwdriver. but still need to know the kungfu. too tight not good. too lose not good oso

4.this i know abit...not much
need to do pressure leak test. if this is the case, you need skilled machine shop foreman to regrind for you

5.this understand abit 
if this is the case you need to rebore and change to oversize piston set