Don't sacrifice morals for a quick buck — At the outset, you'll want to do all sorts of things to make money online, but don't sacrifice your morals for a quick buck. Not only will you put people off, but you'll lose Google's trust. You also shouldn't concern yourself with things like Adsense or other ads on a blog before you have around 100,000 visitors per day. Yes, per day.
The easiest way to find affiliate programs to promote is to check if the people selling products and services you love have an affiliate program – assuming those products and services would be relevant to the visitors to your blog or website. There are also multiple ways to find new quality products or services to promote to your audience based on their interests. You'll find more information on how to do this here.
How much will you make? I think my best month with Google AdSense was almost $5,000 over the last ten years. That amazing month blew my mind since it was actually near the beginning of my blogging journey. When you go from making zero to $5,000 in a month, that will rock your world. For me, it also got me even more excited because I knew there were other ways to monetize.