Beginner rowing machine

Hello!

I (43F) just started working out again after a long hiatus. For now I just to cardio, but I plan on adding stuff later on. I do about 15 minutes rowing, 3 minutes SkiErg, and 25 minutes elliptical trainer. My technique for rowing is getting better but I still don’t know what the heck I am doing lol. My s/m is about 33-38, but I don’t know if that is good/ok or not. I like to get my pulse up and sweat on, and I feel good both during and after that session. But are there some diagrams I can look at for recommended intensity and time, depending on what I want to achieve? Right now I just want to achieve cardiovascular training and strengthen muscles as much as possible. I will move on to strength training eventually but right now I really love cardio lol.

thanks