1) depends on where you live...semi-auto might not be allowed...PA is an example; since I live in PA, I would suggest a good quality & popular bolt action, lever action, or pump action (eg: Remington 700, Winchester 70, or Savage bolt action, Marlin 336 lever action, Remington 760 or 7600 pump action)
2) I would recommend a mainstream caliber that is available in a variety of loads and has a lot of rifles chambered for it (eg: .25-06, 7mm-08, .30-06, .308, .30-30, 7mm Rem Mag, etc)
3) find a load that will fit your needs for all types of terrain & ranges that you will be hunting deer & hog; make sure that load is functional & accurate in your weapon; stockpile that load; practice, practice, practice; most of all...have fun!!!
4) what I have...Savage 111G in .25-06 topped w/ Simmons ProSport 6-21 x 44 (deer & groundhog...mostly groundhog); Marlin 336 in .30-30 topped with Bushnell Trophy 3-9 x 40 (deer, bear, woods walking); dad has a classic PA woods gun...Remington 760 in .30-06 topped with Bushnell Trophy 3-9 x 40 (deer, bear)