Hello, I just got my stock 15" rims balanced and i think they got me big time with a awful job. Is it normal to have a weight missing on one wheel? Dont think so!! Also weight look different sizes. 1 small, another tire medium, next tire a very large weigh . And car dont feel right to me either.

Weights applied to the wheels to balance them will vary in the number/weight required from wheel-to-wheel.
As for the missing one, perhaps no weight was needed to balance it?

Make sure they didn't put your wheel center caps in the wrong direction. They should all be pointing up.

Ok, I guess you have zero understanding of what balancing a wheel means. Weights are put on the wheels to counter balance unevenness in the tires and wheels to make sure the wheel turns uniformly at the end. The number/sizes of the weights entirely depends on how off balance the wheel is after putting on the new tires. It's gonna be different every time you put on new tires as every tire is different and the mounting position is different as well. They'll take off the old weights, replace the tire, inflate it and put it on the wheel balancer. The machine will then measure the balance and tell the tech exactly where to put how many weights to make the wheel balanced, BTW the weights can be on the inner edge of the wheel as well as on the outer edge. After that the machine verifies that the wheel is balanced, or repeat the process until it is.

If the car doesn't feel right afterwards you may have high and low points of the tire and wheel in an unfavorable constellation. To fix and avoid that there is a second balancing method called road force balancing. Not every shop is equipped to road force balance tires. It's a different machine that applies a roller under pressure to the tire while it rotates on the machine to simulate the road force. This will bring out high and low points in the tire and wheel and then the machine will instruct the tech on how much to rotate the tire on the wheel so that the high and low points cancel each other out. There's a certain tolerance of road force that is allowed and it's possible that a particular tire can't be road force balanced, because of a defect in manufacturing and the tire needs to be replaced with a better one. Tire companies will take them back if the shop shows them that it failed road force balancing. Road force balancing will also bring bent wheels to light as they can also result in failure to road force balance the tire.

Lastly, you may require an alignment. During normal driving and hitting bumps, potholes etc. the suspension can and will eventually get knocked out of alignment and needs to be brought back into specs. Many tire shops offer and recommend an alignment at the time the new tires are installed. That's generally recommended to make sure your new tires wear evenly as they are supposed to. It's a good idea to get the alignment checked at least once a year, but definitely when putting on new tires.