Hi and welcome to YT, congratulations on your new baby!
The anxiety is normal on there first couple of days in their new home, it's just because it is a new enviroment with different smells that he is not familiar with.
He will begin to calm down after a few days once he gets used to his new home so dont worry about that.
You may find he will cry in the night a few times for a while, this could be down to needing to go potty or simply because he is missing his mom and litter mates. If he cries in the night and dosnt need to go potty simply move his crate or whatever he is sleeping in near you so he can smell and sense you are there.
When Poppy was really small I found she slept better with a hot water bottle under her bedding and a ticking clock near her bed (heartbeat).
For potty training inside just keep an eye on him, watch for the signs of needing to go potty (sniffing the floor, circling) and take him straight to the potty patch. Give him a command such as "go potty" or "go pee pee" and praise him lots when he goes in the correct place.
If you catch him in the act going potty on the carpet just give a firm no and take him straight to the potty patch and give him the command, then praise him lots when he goes in the correct place.
If you dont catch him in the act but find a puddle/poop on the carpet dont make a fuss just clean it up and try to keep a closer eye on him.
Good luck and cant wait to see pictures of your little one!