You can PvP well with whatever level of funds you choose with some tactical decision making.
Most of my PvP career is in cheap boats… and I’ve colected plenty of blue loot.
If you don’t know your maneuver mechanics, here is a tutorial:
My recommendation is PI in a wh and whatever level of ships that gives you… but learn your mechanics… you’ll be able to win in T1 frigates if that’s how you choose to play.