Every affiliate program offers different commission rates (along with rules that you should know). For example, some programs give out 20% commission, but only on the exact product you posted on your site. In other affiliate programs, you’d receive commissions from any product sale the referred person bought from the store, as long as he/she completed a full checkout within a specific period of time. For example as an Amazon Associate, you are given a 24 hour cookie window.
Google Adwords can be used to drive targeted traffic to a sales page. You simply make an ad in your adwords account then use your affiliate link in the target page URL of the ad. Obviously, you will have to continuously measure the conversions and see if the campaign cost is less than the campaign profit in order to keep the campaign running but I am sure you get the idea.
Please note that some of the links below are affiliate links and at no additional cost to you, I will earn a commission. Know that I only recommend products, tools and learning resources I've personally used and believe are genuinely helpful, not because of the small commissions I make if you decide to purchase them. Most of all, I would never advocate for buying something that you can't afford or that you're not yet ready to implement.