Noone mentioned project wonderful..? Try project wonderful! https://www.projectwonderful.com/
It works most effectively if you play around and find the ad spots that work the best for your comic (it will vary depending on what kind of audience you are trying to reach out to) and use actual money for it, but if you don't have any money to invest, you can go here to read PotooGryphon's advice on how to advertise on there for free!
Oh, and mirrors! Have your webcomic on multiple sites, sometimes a comic works better on one site than the other. Try webtoon and smackjeeves!
With that said, it's the usual: Keep creating content, keep working to improve, respond to comments if/when you get them. Things like this take time but if you've got a big dream it's all worth it