Well, for one thing, the more you work on your comic, the more your art will improve. Seriously! I've been making my comic for 3 years now, and the difference between the first pages and the most recent ones are astronomical in my eyes. xD
You gotta start somewhere! And I say, you can't wait on "getting good." The thing about learning art is that you can always be better at it. There is no stopping point to honing art skills--it's a life long journey. Please enjoy that aspect of it!
Also, if you feel like you could use a boost in draftsmanship, basic forms, perspective... then definitely help yourself out and look into classes. Tutorials only get you so far, and there are a lot of TERRIBLE ones out there that teach bad habits for novice artists. Also, tutorials are usually made as a "step-by-step process" but they don't tell you that they can only do that because of their understanding of form and technique. I feel like this makes beginner artists give up faster because they aren't sure why they can't follow the tutorial, or even if they do they later feel like they can't do that thing any other way. :T
Hey! If you aren't feeling confident, even after starting your comic, definitely apply good practice to the comic while you're learning. That's what I've been doing. And I feel way more confident and satisfied with my pages now!
I highly recommend these free sources:
Proko (An excellent channel with many resources available to artists.)
Marco Bucci (Super talented dude who makes video to simplify some art principles and techniques.)
And if you are able to put money into it, I am a huge supporter of these sources:
Schoolism ($300 for a whole year. This gives you access to over 30 courses with downloadable content, live/recorded webinars, and you can do all of it at your own pace.)
Kat Tsai color class (If you want a MAJOR boost in coloring, her class is the best. She's an excellent teacher, and speaking with her is a delight. I learned so much from the class and got to take recordings and ppts with me to look back on.)
James Gurney's books (If you don't have a couple hundred bucks to spend on Tsai's class, check out Gurney's book on light and color. It is FANTASTIC. The principles he goes over can be applied to any type of coloring, including digital. It's invaluable.)
Best of luck with the comic!!