If you have bare metal you will need to condition the metal before you paint. Deoxidine should be used to neutralize the metal. Once that is done it needs to be painted with etch primer. After that you can put the primer on then your topcoats and clear.
As for painting this time of year you must make sure its the correct temperature for the paint to flash of between coats, topcoat is very critical of cold weather because if its too cold the pain with bloom and you will not a any shine of the paint if your painting with gloss paint.
Being a novice with little experience id suggest dropping the candy and getting some practice swinging a gun first.
Laying down an even candy takes practice and skill to get it on.
Cudos for havin a go though
Good Work Sir
Me like colour
very nice job mate