Try not to be too nervous, but I totally feel that! I've only started uploading since October myself and taking that first leap is intimidating!
I'll feed a few recommendations that can maybe help getting started easier tho:
It'll never be good enough, so feel free to start way before that! Seriously- part of being an artist is that your drawing's always getting better as you draw more, and we're also often our own worst critic. As long as it's "good enough" you should just get started, it'll continue to improve over time! This includes consistency too... I have consistency issues still but it's not something my readers have complained about yet and I'm working on it haha
This kinda depends. How long of a story are you planning? If it's long definitely make sure you at least have the basic plot points mapped out from beginning to end. Starting a long story with little structure can lead to a general lack of focus and potential plot holes/issues. Not to say you have to have every detail planned out first (in fact don't do this xD) but it's useful to know what points A, B, C, & D are so you can at least continue steering the story in the right direction as you go. Maybe you hit sub plot A.5 but after that's done continue on towards B!
BUUUUUUUT
I would personally recommend you start with one or more short stories before hopping into a long one myself. Maybe some that are like between 10-50 pages long each. There are a number of associated advantages to this:
- When a project's short, you can feasibly complete it.
Writing some complete stories front to back is important to learn how to end stories properly (which may never happen with a long project). Also it just feels good to finish things xD
- You can use short projects to learn how to make comics better.
This ties back into "your art gets better over time": when you're first starting out you'll probably not know yet how to effectively use panels, lay dialogue, get a feel for how much or how little dialogue to include, etc. You can also feel free to be really experimental in a short story w/o feeling like you're tied down for 20 chapters with that experiment xD
- You can get your "test pages" out of the way and start the next story off stronger
After you complete a number of pages and get into the flow, your pages will be much better. It's useful to have these "test pages" in short projects so that you don't look back on the early pages of your long series and be like "crap I had no idea what i was doing and now that's the first impression everyone who reads my story gets". Granted that'll still happen since you'll keep getting better... but each new story will start off stronger than the last. First impressions count, and all that.
I guess the tl;dr of that is consider starting with a short story to get a feel for comic-ing, even if it's just like a "pilot episode" for a bigger story you want to tell. Making comics is already scary enough, so don't feel the need to necessarily rush into a giant epic project right away ^^ If you do go this route, I would advise you quickly write something up and just hop right on in. The best way to learn is to do!