Is there a disc brake kits out there that can be add to a bike that now has a brake system that uses the pads squeezed against the rim as a brake. I am new here so sorry about not knowing the right terms.

Bike frame has to already be made so there are places to mount the caliper,
on them.

Some bikes do this, so the Upgrade is possible, they may sell a rim brake bike
with disc ready hubs also.

If neither of these details are on your bike,
a wheel rebuild around Drum brake hubs will work on bikes
without the frame mounting tabs.. good foul-weather stopping.

Or you should look for a new bike with disc brakes on it already..

You can get this conversion kit for canti/V-brake mount 135mm rear ends https://2btherapy.com/bikes/brake-therapy-conversion-kit and install a disc compatible front fork. No solution if you are currently on caliper brakes or narrower frame.

By the time you have bought all the necessary stuff (and it mounts up) balance of investment might favour a 'new to you' bike that already has discs, so best to do the sums first.

Have to ask; driven by fashion (nothing wrong with that) or driven by braking performance? There is a weight premium...