You always Wonder about the Old Threads an the Path They Took
You can do both, but also keep in mind a few things
Residential typically pays quicker(atleast how I had things go), so if you can't wait 30-60 days for money be careful how much commercial you take on or else you will sink.
Residential you can typically get away with less power full equipment and without heat, and use their water. Commercial to make money you need gpm and heat most times. They sometimes will have water, but you have a better chance of running into jobs where you have to bring it with you.
You break something accidentally in residential you run to home depot, you break something in commercial you pray you have enough insurance.
Looking at your ages, focus on residential, but take commercial if or when it comes your way and you are confident in your knowledge and equipment. The money looks great, but if you can get the residential side going well you will be well ahead of those your age flipping burgers for the summer.