Kinda depends what you mean by enjoying the game Since you are asking about HP requirements, I guess you meant for bossing You may refer to this thread for rough estimation - https://royals.ms/forum/threads/common-big-bosses-info-how-much-hp-to-tank.129971/
It really depends on your goals and if you want to be reliant on hyper body or not. I would personally wash to around 16-17k hp by 175 so you can sustain a hit from toad without hyper body. This also allows you to tank bigfoot (one of the best area bosses you can kill as a buccaneer imo), and certain parts of horntail without dying.