Okay, don't panic there's a lot of things that can go wrong and most of them are easy to fix.
You are supporting Skizz via Patreon right? $10 a month Tier is the right one.
Use the Connected Apps section of Patreon's settings to connect your discord and be added to the Skizzlecraft Discord.
If you're not automatically added, open your discord settings then under Connections make sure you've clicked "Join" for the Skizzlecraft discord. User Settings> Connections>Sub Enabled Servers (See the image).
If at any stage something doesn't look like it worked right, such as you did not get a Discord Invite after linking Discord to Patreon, we've found that turning it off and on again is usually the best way to get technology to work, so disconnect your discord app to Patreon and reconnect. We have also noticed that some Browser extensions (some spell checkers, screen-readers and dyslexia assistants) can interfere with the Patreon website, so we recommend turning off any extensions or plug-ins in your browser, if you are having any issues.
Watch the Video below and connect your accounts to minecraftauth.me
Once you've done that Open Java Minecraft in a 1.21.1 instance (we try to keep up to date, plug-ins allowing).
Select Multiplayer, then click 'Add Server' and put play.skizzleman.com as the server address.
Click 'Done' then 'Join Server'. You will be given a Code
Left click on @BuddehBotSRV in discord and DM the code to @BuddehBotSRV
You should now be able to log in.