If you are short on cash, buy a cheap pump shotgun then look at one of the budget priced rifles like the Ruger American or Savage Axis. Or buy used. Lots of used guns online for sale. Just beware some guys want 110% of new !!
I wouldn't even consider using slugs to hunt with in BC.
Get a .308. Recoil is okay and plenty of inexpensive ammo for it.