Before you start hunting there's a few things you need to realise. Hunting with dogs is a big commitment if you are gunna take it seriously.
Having somewhere to hunt is the hardest part of hunting. I wouldn't even consider getting a hunting dog without having legal access to somewhere to hunt.
You wont make a decent dog hunting every six months, you need to get out regularly. If you're not willing to commit most of your spare time to hunting don't hunt with dogs, buy a gun or a bow - they won't be any better or worse if you don't take them out for six months
If your mates hunt with dogs:
tag along as often as you can
realise it's not their job to put you onto pigs, if you get your own dogs you'll need your own spots - remember not to forget the blokes who got you started.
If you haven't been there when a dog has been ripped up bad and you need to drop your plans, do what you can to look after the dog and get to the vets asap, keep tagging along till that happens and see if you've still got an appetite for it. Dog hunting is awesome when it all goes good but the occasions it goes bad and you need to forget yourself and back your dog up are hard and not everyone is cut out for it.
If you can't afford food bills, trackers, breastplates, worming and the occasional large, unplanned vet bill forget owning a hunting dog. I've seen lots of people get into hunting and then neglect their dogs because they couldn't afford the upkeep.
If you tick all the boxes and still want to get started avoid buying a going dog from randoms on the internet. No one sells their good dogs to just random blokes. Get a pup from someone who catches good pigs regularly, hunt it regularly, keep it in the best condition possible and run it with as many good dogs as possible and you have a good chance of making a good dog from scratch.