Q1: It works like any other website, you make a profile, give yourself a profile, upload pictures, and comment. What deviantart has that other sites don't are groups and the ability to make them. You can join any numbee of groups and each one is based on a different thing, some on certain fandoms, others based on original species.

Q2: Yes & no, Yes because it's filled to the brim with lots and lots of artist of every type, and you get to see lots of different styles. No because getting noticed and getting comments on their is rather difficult, heck even getting follows can be pretty darn difficult unless you upload and comment on peoples post daily.

Q3: No you don't, it's entirely free to use. It is however possible to buy a "Core membership" which gives you bonus features, like the ability to create polls, change the background and overall entire look of your profile page, ect. Core is not required for normal use though.

It's extremely.... deviant. I deleted mine because of several occasions where people would blow a fuse over nothing, and make posts about me like a witch hunt instead of privately talking it out. And you WILL see things you wish you didn't! :'''0

However, you don't need to pay anything and it's extremely easy to use on the computer. (Last time I checked, the app needed serious work) but you can use it on your phone too.

I hope you find something that works for you though!

4: It works with all devices, in my experience however it seems to work best on pc.

5: Nope, you just make it an account and your free to change it whenever you want. Though be aware you can't change your username once you've decided it, without a core membership you'll be stuck with whatever username you choose. (And even with core there's limitations to that.

6: To upload something (I've never uploaded on mobile before so i'm not sure exactly how it would work there) somewhere at the top of the screen, there should be a "Submit" option, thats how you get to the screen where you choose the image you want to upload, write the desc, add tags, and choose what section to post it to.

last one: In all honesty, yes, the earlier you start on deviantart the more time you'll have to build an audience, cause it can take a serious amount of time sometimes to get people interested in your work. And if you want to make art a career your gonna need an audience.

Though honestly i'd recommend instagram over DA anytime.

I honestly don't like it that much. I only made one because I wanted to post my traditional art somewhere since I couldn't on Colors. But I do use it every now and then. I am much more comfortable posting my art on IG as well. Personally, DA is for artists who are really popular. Otherwise, no one cares to comment or even like anything. And people can be rude for no reason, too.

I have a deviantart and I like it well enough but I find I spend more time on Insta. DeviantArt can have some,,,,,,weird shiz. Plus Instagram is easier to gain a following and get comments. DeviantArt is very lowkey and hard to get noticed/popular/comments

Hpw does it work is kinda a big question, but do you have to pay for anything? no, you don't have to but there are somethings like special accounts that give you more options for decorating your page, and deviantart has a currency called points you can buy but you could just sell art/designs etc for it. people use paypal there a lot too

there's a mobile app, but i can't entirely reccomend it. oftentime people have trouble commenting, etc.
i would recomend it though, i personally love deviantart