Building trumpeter Tu95 1/72 need help

Depends on the finish, if it's natural metal you may not want or need a clear coat.  If it's a grey maritime version the TS-80 should work.  I just started using the XF-86 flat clear which may be the same thing.

That would not be my pick for a first aircraft model, a simple quick buiold to learn finishing techniques would be good.  In my experience aircraft finishing is less forgiving than armor, and natural metal is the least forgiving of all.

i thought ts79 semi gloss would be better for aircraft look instead of ta80 flat clear . should it have a flat finish or gloss? 

Unless it's an airliner or civil aircraft itwouldn't be gloss.  Some people like a finish less than glossy on small scale airplanes of that type even.  Gloss might be OK for a natural metal airplane.  Best to look at photos and make up your own mind about what you like.