New SEO project

What a fantastic day!
I'm starting a new SEO project for which I need some well-established websites to work with.
Ideally, I would like to find websites with a small revenue stream of around € 100 / month.

The website must be at least 3 years old and we need historical Google Analytics data. As we see it there are two ways to do it.
1. Buy interesting prospects and work on them.
2. Collaborate with someone who wants help with their sites.

My questions are:
1. Anyone interested in selling an old site with low income, for example, Adsense or affiliate marketing?
2. Any recommendations where you can start looking for these types of sites?
3. Anyone interested in collaborating?

It would be fun to discuss this matter further!

Be happy, be lucky!