Your community keeps its characters, adventure schedule and world lore here on WestMarches.games, and uses Discord to talk and play. So you'll need both.
I built the site, and I've joined a few West Marches games as a player myself. The first week in a new one is a lot (new people, new channels, new house rules), so this page sticks to what you do on the site. The house rules come from your community.
Join your community's Discord server, then sign in on WestMarches.games with the same Discord account. The site reads your roles on that server to decide what you can do.
Making a character and signing up for adventures both need the Player role. If you can't see a Create Character button, you don't have it yet, so ask one of the admins. Some communities only hand it out once you've introduced yourself.
Open Characters in your community and create one. Read the guidelines at the top of the form first. They're your community's rules for what's allowed, and they differ from one community to the next. If your community rolls for ability scores, the form also has a Roll for Stats button, and the site does the rolling.
The site isn't a character sheet. It tracks your level, experience and money, and where each of them came from. Keep your full sheet wherever you like, such as D&D Beyond, and paste its link into Character Sheet URL. With a D&D Beyond link, your GM can also see your stats on their DM screen during the adventure.
Your community may want a GM to approve new characters. Until one does, yours shows Awaiting Approval and can't sign up for adventures. It also gets a post in the community's Discord characters channel if there is one, and that's the place to answer questions about it.
Your player profile has a Notes to GMs field that only you and the community's GMs can read. Put anything there that helps them run a good game for you, like topics you'd rather avoid or when you can usually play. You get to your profile from your name on any of your characters.
I'd fill it in before your first signup. A GM you've never played with has no other way of knowing.
GMs post adventures on the Adventures page, and each one also gets a post in Discord with a link to sign up. Pick which character to bring. The signup shows the level range, and times are in your own timezone.
A full adventure still takes signups, but you might end up on a waitlist. Depending on the adventure, you're accepted straight away or once the GM has looked at your signup. Can't make it after all? Use Withdraw from session on the adventure page.
The bot can DM you when your signup is approved or turned down, and when you get rewards. Both are off until you switch them on under Account → Settings → Discord DM Preferences.
Questions for the GM and the rest of the group go in the adventure's Discord thread. I'd say hi there before the session too, so you aren't all strangers when it starts.
On servers with the WestMarches.games bot, you can post in character. Run /wmg character to pick one of your characters, then /say to post a message under that character's name and picture.
It's only really useful if your community has roleplay channels or runs adventures in text. Otherwise you won't miss it.
Running the community instead? Start with Getting Started.