Basically look at anything YC (short for Y Combinator) does they are debatably one of the best accelerators around!
They helped bring up: Stripe, Airbnb, DoorDash, Dropbox, Twitch, Coinbase, Reddit, Instacart, Zapier, Gusto, Segment, GitLab, Webflow, Lambda School, Heroku, Substack, Our World In Data ...
How to start a startup (Lecture series prior to Startup School):
Future founders course:
Request for Startups (List of what YC would like to fund):