Should I do this?

Good morning! Just joined this group. As I have already mentioned, I’m new to art. I have dabbled in charcoal, watercolour, pointillism, colour pencils, soft pastels, graphite and fine liner ink. Sounds a lot but each has been covered in my two hour art session on a weekly course. Tasters really. My question is should I learn all the technical stuff? I’m loving art but do I really need to waste time on the endless practice of cubes, spheres etc. I’m 70 and am loving this. So little time and so much to do. Will there come a point where I can’t improve because I didn’t do that groundwork?