How world I change the front coil sring amd should I get the hole kit

To me it reads like you need to replace the front struts. You can do just the springs but you need special equipment and it is kind of dangerous if you haven't done it before - doable? Yes, but you need to compress the spring even after removing it, then you need to compress the replacement part, adjust the bolt, then release it - not exactly something you do on a whim. I would replace the strut assembly with the spring. It's dangerous to the point some cut the broken spring enough to not damage the struts to avoid the risk!

Without the year of the car I can't locate the SM but pretty much anything pre 2016 is leaked and the sealing points are so spoiled Hyundai can't do a thing. Take your model year, and look for it that way. You will also need to get the wheels aligned as it will mess with that, and you'll need to do both as the ride will be inconsistent unless you adjust the good one after swapping the bad one.

I am not going to link my sources to protect them from Hyundai's lawyers who got greedy when RtR meant they charged for 2016+ but here's the SM:

295 Hyundai Sonata I45 Workshop Service Manual 2009 2014 [Chassis YF] -- verify it will work for you before you use it.