Marketing for early stage startups

As the founder of an early-stage edtech startup, I've been a little "overwhelmed" with which social media platforms to stick with. I'm not sure which ones to invest most of my time into and which to steer clear of.

Given that target audiences vary between different companies, how successful have you found TikTok, Instagram, LinkedIn, Reddit, and even Product Hunt in gaining traction for your company? Have you spent the money investing in advertisements or "promotions?" Was it worth it?

I've gotten over 100k+ views on some videos, but they haven't been particularly effective in terms of conversions.

Have you found office vibes, product demos, or day in the life's to be most impactful in converting?

Let me know would love to hear from you guys!