Heya! I'd follow what the others are saying here. All great advice.
However, I do have a tip if you are also going to be posting your comic on another Tapas-like platform such as Webtoons or something...
Don't post your comic right away. Go to their forums, chat with people, ask questions, make friends, talk up your comic in advance. People will ask for a release date, and it's usually good to do it months in advance if you can. Then, on release date, you'll have loads of people flooding to it.
I received this advice a while back, and it helped me tremendously to get off the ground super quickly when I first released my comic on Tapas! You gotta hype things up, subtly and with grace but also showing how into your work you are. xD it's a balance, and it's definitely something to do when you are on another comic hosting platform.
You'll get there on Tapas, though! Especially if you follow good advices on here. @wolflu66 basically gave you your best way of gaining subs now that your comic is already out on Tapas.