my first pup

Be patient, sit or lay down and let him eat out of your hands.
After a while sit some distance from him with his food and let him come to you. then after a while have him follow you for a short distance, sit down and let him eat from your hand. Talk to him a lot in soft tones. try not to get mad at him at this point. A pup like this is usually kind of soft and any handle you want on him as an adult comes easy anyway. What he needs right now is to grow to trust you. Anger or disipline he doese not understand will undermind this end. Shyness is usually genetic however you saying you had to go under the porch to get him tells me he had not been handled prior. early handling is very important especially if a pup comes from dogs that lean toward shyness.
I had a friend who had a dog like this. She wound not come to anyone but him, kind of. Some times after we loaded the other dogs after a hunt, we would have to drive down the road a ways and then stop again before she would load. The reason he put up with this is that she was a hog finding fool. If your pup is already baying the cat, and she had not been handled before you got her, I'd be kind and patient and give her a chance.

Bob Manning