Ooh a webcomic! As someone who has been drawing a web manga for the past four years, I hope you don't mind if I share some advice with you
1) As it's your first try,
keep it short. I know this advice is usually given to first time game makers too, but seriously, my biggest regret is making my comic too long. It's so easy to underestimate how long it will take, even a one shot is still a big time sink. Rather than trying to make something super deep, to find you get bored of the story/don't enjoy comic making, or just aren't ready for it, and drop it, (which, by the way, really sucks as it will probably knock your confidence about making another one in the future, and you can easily build a reputation as "someone who never finishes anything" & people will stop even trying to look at what you make.) I really
beg of you suggest, that you don't make my mistake, and just try to keep it short and sweet :3c
2) Do a bit of research about where you're going to host the comic. I'd recommend a comic hosting site, rather than just trying to put it in an isolated place like tumblr. Comic hosting sites already have visitors who look at them hungry for more stuff to read, so it's a good way to start your reader base. The different sites tend to have a few genres that stick out as being more popular, so finding the site that matches your comic genre will help you attract more readers. However, don't be disappointed if you aren't immediately super popular and get loads of comments. When you're just starting, there isn't a lot for a reader to form an opinion on. For the first three years, I only ever got comments off the same two readers, but in the past year, my number of readers has shot up

Just give it time, if you enjoy and love your comic, other people are sure to as well!
In case all my advice so far seems a little scary, here's my last one-
3) Making a comic is probably the best thing you'll ever do for your art. You already draw a lot, so making a comic probably isn't going to inspire you to practice even more, but what it will do, is push you out of your comfort zone. Drawing different angles, action, backgrounds, trying to keep a character consistent, they're all things we tend to avoid thinking about when just making little doodles. When you're doing a comic however, you have to pay attention to them. When I started mine, I'd hardly drawn guys before... and the two protagonists of my comic are men

It really helped me see where I was lacking, and gave me the chance to practice and improve. It's both a frustrating and inspiring experience, but I think it's worth it.
Uh, I hope you don't find this patronising. It's just some stuff I really wish someone had told me before I started, so I wanted to share it with you.