It seems to me that the only way to find out if you can do it, is to try it and see how he reacts and whether it's something you want to continue.
Since he's only a puppy you should have very few problems and it will probably take you several sessions to get the cut you want.
One thing I would find out tho is whether there are any areas on a schnauzer that should not be cut because it will not grow back properly. I know on my GR it wasn't recommended that his chest hair and beard be cut because it would never grow back properly. The schnauzer may have similar grooming issues. I found several websites about how to groom a schnauzer as well as a few You Tube videos that you may want to look at.
Grooming a Schnauzer: Mini, Miniature or Giant Information and diagrams
Grooming a Schnauzer You Tube Video
Grooming Your Miniature Schnauzer
A Guide to Standard Schnauzer Grooming
There are many tools a groomer uses besides electric clippers to do their job and you may want to look into what you need to complete Dash's grooming. There are a number of websites where you can order the tools or locations of pet stores where you can buy the equipment. I have never ordered grooming tools online but others here,may have.
Grooming is also health related as the groomers know what to look for while they groom an animal that may be abnormal, an infection that is starting, a problem with the animals coat that can be fixed with additional supplements etc. etc.
MINIATURE SCHNAUZER — BREED DESCRIPTION & INFORMATION
Standard Schnauzer — Breed Description & Information
I noticed while getting these links that schnauzers need grooming frequently so I can understand why you want to learn to do it yourself. Good luck
