Can I go ahead and get everything set up or do I have to wait for launch? I tried installing them through curseforge but nothing is showing up at the character selection like they normally would, am I being a scrub or is it just not showing up yet?

You'll have to download the .zip then take what's inside the .zip and move it to where classic is installed.

Questie.zip (Open it) then you'll see a folder named "Questie" Drag that into where your classic installation is.

for me it's

so drag your addon into _classic_ -> Interface -> Addons

Thanks for the reply. Turns out to make it work with the twitch client I just had to do a scan of my games so that it added classic to the drop down menu. Then you can just let twitch do it automatically.

Remember that you can always download Twitch app and go to "Mods" windows, it will search for any installed game and you can begin to browse addons there.
I find out that 8.2 addons also work for Classic.