Reddit main page is just comedy and politics. You'll want to check out the niches like its Rust community. Other language-based communities as of late have favored chat-type environments over forums.
Reddit doesn't necessarily have a "main page". I generally don't subscribe to any sub that you would typically see in /r/all, and stick with niche subs instead.
If you don't log into Reddit and just visit <old.reddit.com>, that's what I mean by main page. Reddit has a main page, and you don't have to click anywhere to get there.