Potential new player questions

A friend and I are thinking of trying out classic here soon and have a few questions.​If our main end goal is to PvP should we roll on a PvE or PvP server? We don't much care for wPvP but aren't opposed to it if it isn't going to be constant ganking while leveling in some of the contested zones.How much endgame PvP would we need to do in order to be competitive in PvP or, is there some kind of vendor for low tier PvP gear like there was in MoP?Based on the two above questions which server should we roll on? We'd be going with the Alliance most likely.​Thanks for any help in advance!