I am new to Darebee. 62 year old male. Relatively active but 20 pounds overweight. I wish to focus on upper body strength (I do walking and some biking for lower body). Which program and what weight dumbbells should I do
You may use kettlebells so to have cardio and strength in one , you may start with a 12-16 kg kettlebell and a 8kg for upper body exercises, darebee has a kettlebell program
Regarding the weight of the dumbbells or kettlebells you need to experiment with different weights. A good/rough aim is a weight with which you can complete 10 reps of the basic/classic dumbbell exercises. It really varies quite a lot depending on how much strength training you did up to now. E.g. for dumbbell curls 5kg might be plenty for the one guy and the other curls 20kg without problems.
If you don't have access to a bunch of dumbbells/kettlebells (like in a gym) you could also try/test with some different heavy household items. Basically to get a rough idea how much weight does challenge you (for e.g. 10 reps).