So OK. I'll try to write it much easier.And you don't need to apologize me at all. I must do it. Because it means my English is still not enouh good.
There are a couple of ways to make decals yourself.
1. It should be purchased a clear decal sheet.Then it should be painted with white colour ( an airbrush is very useful for that ).When the white paint on the decal sheet is dried, you can print red numbers of the proper shape ( style) but without the white outline on it.Having the red paint dried you have to cut these numbers off from the decal sheet.Of course you have to cut them off with the white outline of the proper dimension.And your decal numbers are ready to be applied on model like these ones you can buy in a hobby shop or these included to the kit.
2.The clear decal sheet like above.Then you have to print the red numbers of correct shapes without white outline . For that you can use a paper sheet for printers ( for instance ) or a sheet of adhesive foil ( it can be white with matt or gloss facture).Then cut off these numbers from the paper or foil sheet.Make it accuratelly because these sheets will be your masks.Use for that a sharp scalpel razor or blade razor.Then put these masks on the white painted clear decal sheet and spray it with the red colour.Contrary to the adhesive foil the papar sheet has to be better sticked to the decal sheet.When the red is dried remove masks from the decal sheet and you have red numbers on a white background.Then cutting off with white outline and putting on model like decals mentioned above.
3. The clear decal sheet is not necessary but....Paint the areas on your model where these numbers have to be applied, with the white colour.When the paint is drying , print on the adhesive foil whole numbers ( with white outline, in the case it is not important of what colour the numbers outline is.It can be red too.It is important to print numbers in a whole size).Then cut these numbers off the foil sheet and stick them to these white painted areas on the model at the correct positions.Leave them at these positions up to finishing of painting camo pattern ( I mean when the model is almost finished and there is the decal applaing time).Then remove these numbers from fuselage (for example).The white background should be under them.The next step is, or you will print these numbers with red paint ( no outline) on the clear decal sheet and then cut them off from the decal sheet and apply to the white places in that way to get the white outline, or you make masks for the red numbers like in No.2 and set ( stick) these mask in a correct position on fuselage ( for example) then you can spray with the red paint.In the case the masks have to be big enough to screen the model in order to not overspray closer surfaces on the model.
4. The "sandwich" method. Paint the clear decal sheet with white.Print both red numbers ( no white outline) and numbers as the outer black outline ( the inner part of these numbers have to be transparent (no colour)).Of course these numbers have to have the dimension of red numbers + white outline.Then cut them off with no black outline.Cut off these red ones aswell.Apply these white numbers on fuselage ( for instance) and then these red ones on those white.Set these red numbers on correct positions in order to get the white outline.
Ufff...Is now better ?