Dumbbells starter advice

[SeniorStud]

I think I originally accidentally posted this in the wrong forum.

I'm seventy-five, been an athlete all my life. I'm slim, 5'9" - 140. I would like to build up my upper body at least some - shoulders, neck, biceps, chest.

I cannot do heavy lifting for a variety of reasons, and would just like to do some weight/strength training exercises at home with dumbbells. I would like some advice on how to get started, in particular what weight dumbbells to get. I was thinking 3-5-10, but could use some expert advice.

Also need a sensible progressive regimen - how to start, when to increase, etc. And exercises for the upper body. My doctor said I'm fine to do this.

Appreciate any help. Thanks.