Catahoula/lab needs training

There is a thing you can do in an enclosed clear space that is energetic and tiring AND teaches the dog's name. The dog needs to be hungry for this.

I throw food.. and say Get it! and just as the dog gets it say the dog's name and run away a couple of steps and when he gets to you face him and have food in my hand that you give. Start with a short distance so the dog gets the idea and then increase both distance and speed. It must be done indoors so the dog can see the food. What you do not want is the dog searching for the food. In fact, as you throw the food away from you, you want him to see it roll when it hits the floor.

This can become very fast paced and fun for the dog.

This also starts to reinforce recall (and it is never bad to reinforce recall). It teaches the dog it is always a good thing to come to you.

Stand next to him say his name and give him a treat. Do this over again moving around the room. When he starts catching on have someone hold him and go into another room. When you call him have the person let go. He will come right to you when you call his name. Do this over again then hide in harder places ( hide and seek) this will teach him a stronger recall as well.
He needs lots of walks to help him calm down. You can buy a Bitter Apple spray at a pet store and spray that on you. It is harmless to dogs and people. He shouldn’t like the taste and teach him the off word. You can do this by keeping a treat in both hands spread apart. He will try and get one from one hand so make sure the treats are held in your fist palms down. When his is trying to get a treat from one hand say off or no. Repeat till he gives up and try’s the other hand, then open to give the treat with a lot of praise. When he learns the word you use that word to get him to stop mouthing. There is so much more to say but to much to write. Your best bet is to start with this and call a trainer. Their expensive so write your questions down for them. You might just need one visit for the mouthing. I would also sign up for a obedience class. You won’t regret that class at all.