Paint needed
Take your wing Aires (cord times span) multiple by 3. You now have the approximate aeria of the intire plane. Check with the paint manufacturer on coverage of paint. That’ll generally have a formula. Then get a little extra to practice with. Remember a pint after mixing reducer etc often nearly doubles the amount you can apply, but it (the reducer, flex agent etcetra) flashes off. I’m old school so dust coat befor first coat then wate appropriate time fore second coat. Watch for orngpeel (not enough flow/paint. Runs too much paint). Have fun and try not to stress over it.
One caveat prep is everything. And cleanliness is the difference between a good paint job and a fair one.
Hope this helps RD