If you're a total newbie then I would advise you to get a course, mentor/coach or simply do a search on Youtube about PPC. Check out blogs as well to learn more info and up-to-date strategies that will help you save a lot of cash.
That's what you should do first, invest in the knowledge first, either trade time or money. By choosing time then you'll have to do research on your own to get great techniques that work, you'll be trading hours of your time online or at the library (which could be a waste of time). When you choose money then you simply buy a course, book or maybe get coaching.
Once you have some basic knowledge then you have half of the battle won.
There's no best PPC site for every niche or offer. Do some research to find out what's working for your market.
Go to clickbank, check which offers are the best sellers in your niche. Most of those sites get a lot of PPC traffic. You can also type your keyword/niche (go as broad as possible don't niche the search) on Google, see if any of the top 10 results are using any ppc traffic. That's how you'll find out what ppc network most people use in your market. Use tools such as SemRush or Spyfu to see if people in your market are using Paid Search or Display Ads.
These tools will allow you to see whether they use Bing, Adwords or any other network then you simply choose the ones you feel comfortable with, do some research then apply the knowledge. Repeat the process till you get it right and make it your best ppc site.
The most popular ppc sites are: Facebook Ads, Bing Ads, Adwords, AdRoll, LinkedIn and Twitter.