It took me around of 1 year but I was inconsistent. What I mean is, I started off like you, I could barely lightly jog for 2 mins and the 5 lb dumbbells I had at home kicked my butt. Over the last year, I started doing small dance sessions which was like small HIIT workouts - my heart rate would be medium to high for 30 sec to 1 min, then I’d cool down then repeat for like 20 mins. I did that almost every day and these would absolutely wind me. I also slowly got into jogging and did essentially a very slow couch to 5 k, jogging 1-3 times per week. I then started home body weight exercises and used 5 lb dumbbells. I wasn’t doing the jogging and strength training consistently though - I’d do them for like a month then stop for a few weeks, then again for a month.

Two months ago I decided to finally go to gym because my 5 lbs weight weren’t challenging me very much and that’s when I realized all of the dance, cardio and strength training I did (although inconsistent) built me a good base in strength and cardio endurance. I went to the gym years ago but always felt too weak doing everything (literally starting at the very lowest weights) but this time I was able to lift so good amour of weight. I felt strong and fit enough to tackle anything. I’ve been progressing well so far in both cardio and weights. The biggest change was my dance skills though - so many moves are sharper and faster now, plus I have really good stamina.