The front hood at the spring hinge is too high.How can I adjust it so the gap between the front quarter panel and the hood will be not as big.Thanks.

Try checking the basics first. Open the hood and carefully look at it all the way around the hood edge and the body edge where it sits when closed. Check there isn't something trapped or blocking it from closing correctly.
Next check the hinges for the hood. Are they adjustable? You might just need to slacken the hinge mounts when it's closed to let the hood drop into place.
Finally check the hood itself isn't twisted or warped.
An extra check is one that has caught me out. I fitted the hinges back to front on a 'self build' I bought. Took me a while to figure that one out.

Your description indicates the door hinges require adjustment. Usually the striker would be removed and the door hinges adjusted for easy closing and equal gaps. It is likely in your efforts to make the door flush with the front wing, mudguard or fender, the hinges are too far in. Most likely your replacement door is not identical to the original - not unusual for various reasons... Once the door hinges have been adjusted to provide a satisfactory position and closing the striker would be refitted and adjusted so it goes into the catch or latch dead centre - neither lifts nor pulls down the door as it closes. That is where the door needs to be and if it stands proud a little it is just bad luck - often the front fender can be repositioned and then the bonnet or hood readjusted. A competent panel beater would be able to tweak things for you to make them acceptable. It might have been better to fit a new latch to the original door.

There should be fasteners under the hood/bonnet as well as some behind the door. (Near where door hinges attach) and there might be some on the underside of the wheel well. Remove these carefully after you have marked reference points in multiple locations to assist with proper alignment when putting panel back on.

check all the rubber stoppers where the hood closes to see if they are adjusted too high. first thing to try. maybe hood needs adjusting at main mounting hinges on windshield end ?

i had to elongate the hole in the brackets to get a 1/4 in of adjustment from side to side.

There should be rubber bumpers on the bottom of the hood where the latch is. They are located on either side (and ends). Screw them inward for lower closure.

first you go to local book store or dealer or ebay and pick up a chilton or haynes book it will come in handy for the wiring and the hinge torque and allinment specs and tricks

This is a two-person job. Have the bolts in hand and lift the hood over the car's front end and locate it on the hood hinges.
Place the bolts in loosely at first. You'll need to adjust them for proper fit. Open and close the hood to align and tighten the bolts when in the right spot.
Hope this is what you needed to know.

open the hood get a helper and take off the 4 bolts that attach the hood hinges to the car and put that on the ground next take off all the bolts for the fender make sure you get the ones inside the wheel wells and then ur headlight is just a few little bolts and put your new stuff on and your done

The hinge is possibly sprung where it attaches to the body. If it is welded to the body, a body shop will have to fix it. Sometimes you can shim behind the hinge if it is bolted to the body, but, usually not successful.