Actually, I am not, but I want to get back to pvp. I enjoy doing pvm but after 15 years without pvping I feel like I want to come back

I built an ele druid, which was one of my prefered classes back then to pvp, and I didn't really quite like it as much as I used to.

Now I always liked how barb kick ass on pvp, but I never had one. Thing is, char itself is quite expensive and I dont want to buy everything to then realize I dont like its pvp style or how to play it

my question is: is there a way to try out a champion first (like a server where you get all the items) or something like that?

also I would want some info about barb items needed. People have 3 types of build for him as far as im concerned, right?

Barb is expensive because of charms. The three main builds are:
Barb vs barb
Barb vs Caster
Barb vs All

Barb vs all is basically just BVC with enough stats to wear a BVB set which typically means more strength and less life. I'd recommend building BVC.

The charms are what really makes the PvP barb expensive, but they make a big difference. BIS is 3/20/20 sc, slightly less BIS but cheaper is Max/AR/Life large or GC. Skillers are a waste of time.

Basic BVC gear isn't too expensive and hasn't changed much since LOD so those guides are still accurate. Likely the most expensive part is a FCR circlet for a faster cast rate setup, but you can compete without it at the 40FCR bp.

BVB gear is alot more expensive due to being more niche. The WW IAS changes did effect bvb gear so those LOD guides will be out of date now. I believe you need IAS on gear to hit a 4 frame WW which was not required in LOD, as a result I think Grief zweilhander is favoured over BA or CB due to being a faster base.