Its better you prep the paint before going for just a wax/sealant combo. The reason being the wax/sealant wont bond properly with the untreated paint and you wont get the results promised. Also the lasting time will be considerably smaller.
This is how you get the paint prepped.
1) Wash
2) Clay
3) Heavy Abrasive (Compound)
4) Light Abrasive (Polish)
5) Sealant
6) Wax
1) Wash: Since your car hasnt been treated before, its better you get the car washed and use some pre-wax paintwork cleanser. This will remove any old wax/sealant layering from the car. There are products available but if you dont wanna but a pre-wax cleanser, the cheaper solution is to get the car washed with surf/bright/ariel..... These are not recommended once you have detailed your car since they are AIDS to the paintwork.
2) Clay: This is the part where you either buy a clay bar (+Detailing Spray or simply use water) or a clay towel. A clay towel is a little more expensive but easier to use compared to the traditional clay bar (Do a google search how to clay the car). This process will remove almost all of the embedded particles in the paint work that can and cannot be seen with the naked eye. Even before you start the compound process, the paintwork feels alot smoother (google the sandwich bag test of paintwork).
3) Compound: This is the process where you remove major oxidation on the paint, swirls, scratches, etc that can be seen on the paintwork of your body. Modern cars have clear coats on them so you can use a DA to correct the paint. Compounds are a pita to appl and spread by hand and even worse to remove by hand. Thus a DA is the preferred choice. If you do intend on applying it via hands, make sure the paint is clayed before since that makes it relatively easier to apply and remove. Make sure you do this process using straight strokes rather than the traditional circular (if doing by hand). Also dont let it sit for too long on the paint. Apply on a section of a part (eg half the hood), do the other section and then remove the compound from the first section followed by the second section.
4) Polish: Once the heavy abrasive step is done with, use your polish to enhance the finish of the paint and further improve the results. A polish will bring out the gloss, pop the flakes and add depth to the paint work. Apply in circular motion and finish it off in straight lines. Compared to the heavier abrasive, polishes are relatively easier to apply and remove.
5) Sealant*: This goes on first if you have both the wax and sealant in your stock. Dont apply wax followed by a sealant. Sealant tend to last longer compared to waxes. They bond stronger. Mostly come in liquid and a little dop can go a long wax (One tiny drop of my blackfire sealant is enough to cover half a panel e.g half the hood). Sealants tend to last atleast 6 months (some can go for a full year) if the car is properly detailed during that time. What they do, well I'm sure you know that already (H).
6) Wax**: Synthetic and Carnauba..... Waxes are used with and without sealants. Of-course without a sealant, the wax will last a couple of months at max. 1-3 months is what most waxes can achieve. Synthetic waxes are mostly preferred for lighter colored shades since carnauba waxes are meant for darker colors. Well, most of them anyway. There are exceptions where carnauba waxes and synthetic waxes also work on both type of shades. I use Meg's goldclass wax on all my cars (dark and light shades) so its really upto you.
*You can go with multiple layering of paint sealants. This will maximize the paint depth and gloss factor and ensure further durability. Also if you have missed any section in the first application, you can be sure its covered up in the next application.
**Multiple layers of wax on the sealant will also further enhance the paint look making it look wet and slippery, will further increase the durability factor of the sealant and wax combined and make you a very happy man.
I usually go for 2 layers of sealant followed by 2-3 layers of wax.
