I can try to shed some light as to how Discord is quite nice! Through discord I have been able to meet some great new people I'm glad to now call my friends~ Discord also allows the ability to contact peoples in a much more efficient and faster ways, kinda like texting basically~ for some artists I know they only use discord for commission work information rather than emails and most other ways of contact because of this faster/text-like system~ Regarding discord servers, As a server owner myself, You can make a discord server (if you so choose to) easily for free and you can customize it however you'd like! I got my inspiration from checking out other servers to see how they are laid out and structured then I used the basic ideas from their set-ups and made my own unique server out of it~ I hope this helps a bit, you are an amazing artist and I think it'd be really cool to see what your discord would look like if you do choose to use it~ Stay awesome and Best Wishes!

Thanks a lot ^u^
Not sure yet how to meet new people there, I have only found how to set up a server and invite people whose usernames & numbers I already know ^^;

In future, I will be using Discord for commissions -- in fact I've just gotten in contact with one person who I'm doing commissions for just now ^^

No problem! I'm glad to help in whatever ways I can! If you ever would like to ask any more questions my discord ID is @Milo#1881 You're very talented and inspiring with your art dudertron~ I wish ya the best moving forward!

Champ is correct. It's a pretty good way to handle communication for clients though if you want to send things like WIP there's a size limit (I believe it's 8mb). Also if you're interested in a server that can be a good way to communicate with your audience though you'll have quite a few lurkers (I've been known to be one, lol). Another benefit of discord is you can stream in it. So if you ever decided to stream your art process you can do it there, I believe you can host up to 10 people (though there is a temporary increase in that to 50 currently) if you didn't want to go through something like picarto and had a enough small audience.
A lot of artists have a patreon discord server as a reward to interact with people and can be a good way to get to know your community. And some artists have both a patreon and general discord server.
If you do decided to go the server route you'll have to label where you post your art as NSFW channels, otherwise it could get you in some hot water with Discord's TOS, but otherwise it's pretty straight forward.
Not sure if that helps, but I hope it does. :)