I've basically done the same, I dabbled in Demon Souls, Dark Souls 1 and 2, beat Bloodborne, and then I beat Dark Souls 3. For me, I just found the best thing to do is to play defensive. Well armored, sword and shield combo. I rarely did any of the more complicated abilities that might be there, such as parrying and what not, as I was never good with that. Just build up your defense enough, focus on any accessories that enhance your carry weight, and I think the specific skills were...Strength and maybe Vitality/Endurance? It's been awhile, but primarily to play heavy and still be able to roll if you have to, you gotta get that Strength way up there and on the quicker side.
Maybe not the best help, I haven't played Dark Souls 3 since last year, so I'm probably forgetting anything else helpful lol