How do i go about fixing my leaky sunroof if everytime it rains my car if full of water inside? whats the first step please help

Have you checked the fuse . If water penetrated a vital component it is possible you had a short

If you use a guitar string to run down the drain hole followed by compressed air, you should be able to clear the clog.

The sunroof drain hole on the drivers side could possibly be clogged up, allowing water to overflow and drain down the inside of the windshield post and onto the drivers side floor. Have that checked first since it's quite easy to see, with the sunroof opened all the way.

I'm assuming the vehicle has a sunroof, if so you'll need to be sure there are no obstructions like leaves or small sticks keeping the sunroof from completely closing. If the sunroof is closing properly it may be time to replace the weather stripping seal around the sunroof to get the leak stopped. Please rate this answer, thanks.

most likely cause is water intrusion through the cabin filter

pull the filter
if wet then you need to find something that diverts water away
many OEM's have had this problem but nothing on file for this vehicle

The most common source of water on the floor is a plugged a/c evaporator case drain hose. This drain is generally located down low on the engine side of the firewall at the passenger side and is usually a small short open ended hose that points down. Debris and bugs will clog this hose which makes the water that condenses on the evaporator [whenever the a/c is on] overflow and leak out of the heater/air conditioning housing and onto the floor. If it hasn't rained for some time yet you are still getting water on the floor I would bet on this hose being plugged. A puff of compressed air is enough to clean most of them out. Most sunroofs have one or two small drain holes that allow water to run down through the door pillars and onto the ground. If you pour a small amount of water around the top edges of the sunroof when it is closed you should soon see water dripping onto the ground under the outer edge of the vehicle. A few sunroofs just rely on tight weather stripping to keep the water out but those usually drip water on the driver or passenger if they are leaking. I see a lot of leaky windshields but again, it has to be raining for water to get on the floor from them.

How to Repair a Leaking Car Sunroof Repairing a leaky sunroof usually leads to discovering that the sunroof is not the culprit of the leak. Instead dirt and debris may be the likely culprits since they obstruct the drainage tubes or the drain channel that are part of the sunroof's water management system. Once these are obstructed, the water backs up and heads for the nearest escape, which may be to the interior of your car. The following instructions are to help you repair a leaking car sun roof.

1. 1)Use a non-abrasive cleaner with a soft cloth to clean the glass panel and the seal on the outside of the car.2)Open the sunroof after opening the vent shade. Allow the sunroof to open to the vent position but do not let it slide backwards.Wipe and clean the trough that is around the opening of the sunroof. 3)Use a wet cloth to remove any debris that may be preventing a tight seal between the trough and the sunroof's seal.Inspect the seal. 4)Look for any cracks in the seal. If you find any, you will need to replace the seal. Contact the car manufacturer or a repair shop to replace the seal.Check the drainage tubes.5) You can use a small cable or even a coat hanger to gently probe around for a few inches to see if there are any clogs or standing water in the tubes.6)Use a thin cable or coat hanger wire again to try to clear the drainage tubes if they are clogged. Make sure whatever you use does not have a sharp end and apply only a little pressure.7)Verify that any of the standing water in the drainage tubes went down by poking a dry thin cable or wire down an inch or and pulling the wire back out.8)Check that the clogs are completely gone in the drainage tubes by pouring a small amount of water into the tubes.
   also for more help.
   How to Check a Sunroof for Leaks There's nothing nicer than a sunroof in your car, especially on a spring or summer day. Open the sunroof and enjoy the fresh breeze. But check a sunroof carefully for leaks before you buy a used car. It's just good business. 1)Open the sunroof to check for leaks when you are shopping for a used vehicle. First of all, make sure the sunroof opens smoothly and closes securely. A good, snug fit with no cracks or lop-sided setting is a good indication that it won't leak.2)Look carefully around the inside edges of the roof of the car where the sunroof opens. Check a sunroof for leaks by making sure there are no signs of rust or corroded metal around the opening edges. Of course, examine this area while the sunroof is open so that you see all areas on the sunroof opening's edges.3)Check the ceiling inside the vehicle when you check a sunroof for leaks. Look for signs of water stains around the inside ceiling lining of the car at the sunroof's site. Ceiling fabric at the site of the sunroof or around the area of the sunroof that looks spotted or has slight color variations may indicate a sunroof leak.4)See if the car's headliner (the ceiling fabric) is sagging. A leaking sunroof may cause water to run inside the headliner. Water buildup causes the headliner to sag over time.5)Examine the floor of the vehicle carefully when you check a sunroof for leaks. Damp carpet or a mildew smell may indicate a leaking sunroof. Also, look for water stains on seats where water may drip down from the sunroof. This will help. Thanks please keep updated. please do rate the solution positively .thank you for using fixya
   
   

I think it goes through the part where the window and hood meet and slides down because many cars do that

If you have a sunroof, the drain tube on the driver's side A-pillar is probably blocked or disconnected form the sunroof drain.

have the sunroof gasket replaced
or buy one online cheap at sunroof doctor.com

hope2help shack