RIght now I take my puppy on leash to his potty spot. When I can just open the door and send him out?

Is the area secure and the dog will be safe?
How old is the puppy?
How is the house training progressing?

yes my backyard is fenced. There is an actual potty area we made that we always take him too.

house training is good. He goes everytime I take him outside even if its just a little.

he's 13 weeks.

Can you let him out and see what he's doing from in the house? Is there anything he can get into?

well I would plan to always stand at the door with it open and watch him go. but will it confuse him for when I need to have him on a leash and make him go like at somene's house or in public somewhere?
or if I sometimes take him cuz i want him to poop not just pee

i've noticed that i have to sometimes bring him back or tell him he's not done and needs to poop after he pee's cuz he just ate.

If he continues going to the same spot to potty and then comes inside, then you can let him off-leash. But, if he starts playing and goofing off outside instead of doing his business, then you have to continue going outside with his leash on. Some dogs will be let out to go potty, play instead and then come in and go on the floor, all while the owner thinks the dog was pottying outside.
To start, stand at the door with a retractable and let him go out on his own to the potty spot and reward him for going. Pull him back over or walk out with him if he starts to wander. That way you have a "just in case leash" on him if he starts enjoying this new freedom. Then after he is good at going on his own, take the leash off and see how he does. Any backpedaling means putting the leash back on.
It also helps to use a conditioning word, like "go potty" to let him know this is potty time or that he needs to potty. This works off leash and on and you can say it where ever you are at to let him know it's bathroom time. Say it to encourage him to go, & while he is going and then praise him after he goes. He'll soon get the connection.