Body weight exercises are much safer and imo better at solving back issues than moving 30Kg of metal around
Bodyweight programs are effective too, of course. Whatever keeps an individual motivated is usually the best choice for them.
Stretches like bird-dog, cat-cow, bottom to heel stretch, knee to stretch chest, knee rolls, back arch, lunges, bridge, gluteal stretch... (the names are confusion, just look it up and you'll understand). Do them slow, hold the poses, breathe deeply in and especially out.
Do these on a yoga-like mat but thicker (like 1cm, off Amazon). Print some screenshots on to a single piece of paper and you're good to go, at the gym or at home.
Not body weight but real good: full body routines with a kettle bell (Caroline Girvan on YT).
I went to a personal trainer in order to learn proper form, and he told me I wasn't ready for barbell lifting yet. It took about 6 months of body weight / mobility training before I was ready.
Even then I only started squats with bar weight, and went slowly with progressive overload. Same with deadlifts, using a trap bar. If I feel tired one session I just skip or cut the set short.
I'm almost 40 so this very cautious approach helped prevent injury. I recommend everyone talk to an experienced personal trainer before they start a weightlifting routine.