Hello Betasingh!
The very first thing about making models is time doesn´t matter! In order to get well result I stop working on it since have lost enthusiasm :D . Let´s start with small steps. At least it depends on how long the clue as well as the coating needs to dry out.
Today I started the model kit. I think the question about the first step is somewhat special.
1. cleaning -> primer -> withe coat but finish it will be the last step bevor decal!-> cockpit,windows, wheelwell, apu exhaust -> bonding of fuselage shells...
2. yes you will need more than one layer of coat and it´s considered to use a paint system from one supplier.
3. revell clue is pretty fast but it depends also on temperature and humidity. I guess you should take a minimum of 30 min into account.
4. Mostly I apply the solvent after I have set the decals into the model.
4.1 I cut the right decal out of the sheet
4.2 put it in warm water for appr. 10 min until its possible to slide it on the sheet.
4.3 carefully slide the decal on to the surface
4.4 slide it on its final position and carefully wipe off the remaining water
4.5 apply plenty of decal softer on the right decal to get best result.
For more question, have a look to the building blog
kind regards