I set up everything and tried it out, but the prefix isn't working at all. Instead of "&4[Owner]" it just adds the number 4 in front of my name

LP is showing that the prefix is there, that's more going to be on your chat plugin setup

not an LP issue, I'd suggest speaking to the people behind your chat plugin or asking for support on the discord

how do I change that?

Check your chat plugin configuration? Not much we can suggest without that information.

how do I change that?

LP doesn't modify chat, it just stores/provides that information for other plugins, it's up to you to install/configure a chat plugin to fetch that info from LP

You need a chat plugin to display prefixes.

Do you also have Vault?

Maybe read the FAQ on prefixes: https://github.com/lucko/LuckPerms/wiki/FAQ

what chat pl should I use?

its also not working without the chat plugin

Whichever one fits your needs, and supports Vault (assuming you use a Bukkit based server).

what did U use?

There is some examples on the wiki of plugins to use, this issue tracker is for issues with LP, not for discussion/support, please use the discord for that.

I just need a few examples of good plugins, supporting LP (spiggot)

what wiki?

The LuckPerms wiki. Scroll up, you'll find it (I also linked to it earlier).

You'll find the chat plugins on the prefix page.

Ok - another thing, the permisiions arent working, i can switch between the groups and will still have every permission, could be because i'm an op?

You should not use Op when debugging permissions. Please read the FAQ, almost everything you've asked is answered there.

Thx for everything