I too wanted to use adSense in order to drive traffic to my side project. I made a small calculator for estimating dosage in cannabis edibles, which gets a few clicks here and there (https://www.scientificedibles.com).

It turns out that adSense, will not touch any cannabis content with a 10ft pole so it pretty much ruled out getting any traffic via them. There were some more niche advertisers but for those you needed substantially more funds.

In the end, I found that SEO and content were a good alternative (and free!).