How heavy of a dumbbell should I get?

Get a pair of 30lb dumbbells that can be used for many different exercises and will be useful for most of your life no matter how strong you get.

Depends on what you want to build. Either power or endurance. For building power you should be lifting a hevy weight but less times. Only 7 or less reps and 2 or less sets. For bulding endurance you should lift a light weight but do several reps/sets. 8-15 reps and 2 or 3 sets.

I recomend gogin to the sotre and trying out dumbbell dependig on your goal

hope it helps

Here is a break down for you:

If you are going for strength gains your typical dumbell weight should be the dumbells that you can do 4-8 reps with.

If you are going for mass gains your typical dumbell weight should be the dumbelss that you can do 8-12 reps with

if you are going for definition gains your dumbells should be 12-18

And finally endurance is 18+

so strength = 4-8 reps

mass = 8-12 reps

definition = 12-18

endurance 18+