German Shorthaired Pointer Q&A
If you are outdoors with him, that should be enough to keep him happy, provided he is not on a lead. They love to run around exploring. For the indoor times, I find a large variety of toys is needed ranging from ropes to chews.
You can take him on a walk 2 times a day and run around with him in your yard and play catch with him. thats all you really have to do to keep him happy and healthy!
Is the dog alone during the day? If he isn't, it is easy to entertain him. They will let you know. They need a lot of physical and mental stimulation. We have one and we play a lot of ball, my kids will sometimes play hide-n-seek with him. They tell him to stay and they hide somewhere in the house and then they call him. Sometimes I just say "go get Dad" or "where's Jason?" He loves challenges.