Even if you are comfortable trimming the rest of your pup's body, trimming around his face can still be a challenge you may not feel ready for. It can be even more challenging if your pup is not already comfortable with being groomed in the first place.
The younger you start grooming your pup, especially around his face, the easier it will be for you to get used to his face being subjected to regular grooming. There are many smaller breeds and a few larger breeds that need to have the hair on their faces and around their eyes trimmed on a regular basis.
While your dog may like trying to see what's going on around him, he may not like the idea of your hands and a pair of shears being that close to his face. You need to be careful not to cut or nick his face or poke his eyes. Unless your pup is a poodle, you should trim his hair in the direction it flows naturally, which is typically from front to back.
Grooming your pup's face may seem challenging at first and your pup may never actually get to the point where he enjoys having it done. But with plenty of practice and patience, he should at least reach the point where he will stand still while you do it. Try to have fun and stick to a regular schedule, this will make the job a little easier for both of you.