I have never attempted stenciling before, but I will be making a tiered cake with the classic damask stencil on it. I have already decided that I should probably cover the cake in fondant instead of buttercream because everything I have read makes it sound like that will be easier for me for my first time. My question is, should I use buttercream or royal icing for the pattern? The pattern will be white, so I don't have to worry about bleeding, but I just want to make sure I get the right consistency of icing. Any incite would be greatly appreciated. Thanks!

*any other tips to make my first time as painless as possible would also be appreciated

I have used both, it is more about getting it to the right consistency. You don't want it too runny because it will bleed. Too thick and it won't spread right. And make sure your icing or fondant is even the whole way around the cake. If it's not, the stencil won't lay flat and the icing will bleed through.
It's all learning by trial and error!
Hope that helped.

Test out your method before trying it straight on the cake. First stencil onto a work surface or cutting board. Next try using the stencil on a coffee can or other rounded, vertical surface. Doing this means you can check the consistency of your icing and the way you are applying it. Some of the stencils are really tricky, especially if they have big openings in the design (one of the damask designer stencils is like this) because the stencil tends to stick out from the cake and your icing goes under it, no matter what consistency you have. I would try with royal icing on fondant, simply because I think it is easier to clean up than buttercream. Have plenty of cotton ear bud things and a bottle of vodka nearby for patching up mistakes!

thank you so much, great advice!