Marketing and customer acquisition usually involves experimenting with various channels, tweaking & iterating, and doubling down on the ones that perform. You essentially want to be where your target customers "live."

On a high level, your potential channels would be:
- Content Marketing & Social Media (e.g. writing blog posts)
- Paid Ads (Google, Facebook, Twitter)
- PR (get written in startup publications, Product Hunt)
- Partnerships (partner with startups, investors, or accelerators)
- Referral program
- other places where entrepreneurs "live" (forums, communities)

Finally, not exactly an acquisition channel, but I believe branding and community go a long way.

Happy to chat and help in more detail with the specifics on your business.