I just put up a free SEO analyzer you can check out, it will provide all kinds of useful metrics like site speed, a breakdown of improvements that can be made for on-page SEO, social signals, Alexa ranking, and more. I just released this application, let me know what you think!
If you mean "Related Searches" that appear at the bottom of most google searches, you could try a pre-built library such as a web scraper setup to specifically scrape these results.
You could also write your own scraper to pull these results, though you'll have to maintain the scraper as most likely Google will change it's markup over time.
Anyway: that's my advice: Try to make your own SE: https://gitlab.metager3.de/. You may combine the work for your own with the possibility to earn some money: The Hackaton: see: suma-awards.de (german only)