Cake decorating help

[MrsCosmopilite]

I'm a very amateur cake maker. I've volunteered to make a cake for relatives for a big occasion and am planning on making a basic sponge which I'll decorate.
I want to cover the top and sides with colour-themed sprinkles, then put some 'trimming' on that.
I was intending to use coloured sugarpaste and brush over some pearlised colour, but I have no idea how to make the sprinkles stick to it.
Should I abandon that and go for pearlised buttercream (I can mix colour paste and glitter/sheen into it) then put sprinkles on?
How do I get sprinkles onto the sides? Do I roll the cake sideways into them? Do I keep the cake flat and 'press' the sprinkles on?

Sprinkles stick much better to butter cream. Roll or press, depends on crumbliness of cake and the size of your hands (DH could pick up and roll, I'd find it much more awkward).

You can butter cream the sides and fondant the top, quite easily. Just remember if you butter cream everything and then put fondant flowered, letters or other decorations onto it you must let both dry and assemble at the last minute. (DD2 doesn't much like sugar paste)

Sugar paste sucks moisture out of butter cream and goes flop.

I would go for buttercream and sprinkles with sugarpaste decorations (dry at least a few days in advance to do this) or sugarpaste with no sprinkles, they won't stick particularly well to sugarpaste.

You can buy edible glue, which you can put on the sugarpaste and which would make the sprinkles stick. However, this would probably not allow any pearlised colour/sheen to be applied as well, I think you'll have to go for either - or.

Thanks for all the feedback and ideas.
I am going to go for buttercream which I can colour to a toning colour I have some sprinkles, and I've got edible stars, lustre, glitter and pearls.

Thinking of mixing all the decoration together and putting on the sides and top.

I have a cake topper (pre-made) to put on the finished item.

Still undecided about fondant for the top, so will have a look on pinterest for inspiration. :)