I have two dogs, both about 6 years old. When they moved to my house with me, I was scared of leaving them alone. Actually, I only had my bigger dog at that time. Also, I worked long hours then and was scared of leaving her alone a long time. I would leave to go grocery shopping and worried she’d get into something before I got back. Just put anything that’s hazardous to him up and away. That fear does go away, but only with time, or at least it did for me. I still miss them TONS during the day, though! 
Also, you could check out some doggy day care places near you. I know PetSmart and Petco have doggy day care, or they have in the past. You don’t have to take them everyday, but if you can afford it, take them a few times or even once a week. That way, your dog gets socialization with other dogs and it might help you feel like you’re doing something for your dog.
Training is a good idea, too. PetSmart and Petco have that. It can be expensive, a little over $100 for about 6-8 weeks, if I’m remembering right. That will help you learn things, as well as your puppy. My bigger dog went to training. She barked at every dog she saw whenever we went in a store. I took her to training, and after the first (where she barked the WHOLE time–not kidding) and second (where she barked the first 15 min) time, she didn’t bark anymore. We found something that worked for her to stop. It can take training for the whole barking and lunging thing, but also, he’s a puppy and could be excited about meeting other people on walks. 
My dogs follow me everywhere in my house.
That has to do with wanting to be close to you, and you could be considered the pack leader. Mine get in my way constantly!
That’s to be expected, it just means they love me all the more. Sounds like yours loves you already!
Mine sleep with me, too. I can’t stop them, I’ve tried, but they just want to be close to me. I personally don’t mind it, but I know some people don’t want that for their dogs. You could let him sleep there, or get a crate for the nighttime. It really is your opinion there.
Don’t be surprised if your dog messes up in your house. Mine have, it’s just part of the deal with having dogs. I just clean it up and show them I’m not mad, but they need to go outside to pee or whatever. I don’t ever get mad, cause they are dogs. You’ll have to learn their signs for when they want to go out. Some people put bells up by their doors and the dogs ring them. Mine come to me and whine.
I also get toys, toys, toys for them to play with during the day so they don’t get bored. A good way to get dogs to chew on furniture or blinds (like mine have) is to not have anything for them to play with during the day. Of course, they may still destroy something, and that’s par for the course. It may happen, it may not. My blinds still got destroyed even with lots of toys. There is this bitter spray for dogs you can buy, and it works. At least it did for mine. Puppies are notorious for chewing, but they’re great animals to have!
My biggest advice to you would be to don’t give up on your puppy–remember, he is a puppy and still young and learning, and get him into training or doggy day care if you can. Also, look online for tips and tricks for dogs. That’s another way to learn things. I’ve done that as well.
I love my dogs and I wouldn’t trade them for anything! I hate their puppy dog eyes when I leave, but I love their unconditional love and their excitement to see me when I get home. There’s nothing like it in the world! Now I’ve got to go look at your pictures and fall in love with your dog, as I’m sure I will.
“Do I believe in love at first sight? Absolutely. I fall in love with every dog I see.”