[Michele]

Another idea, if you are introducing GURPS to players who never used it: prepare and run a short sample adventure.

Don't ask the players to come up with durable, well-thought-out characters designed for a long campaign. Give them pre-made characters, in general terms satisfying their tastes as you know them, with suitable GURPS skills and Advantages.

Have the adventure feature showcase encounters that explain by way of examples the GURPS rules you'll be using. A typical social encounter, typical basic combat, typical use of non-combat skills, a ranged combat situation, a trickier social encounter that might end badly, a more complicated fight etc.

At this point, I would be telling you to use a pre-made adventure too, but since you have your own setting in mind, this sample adventure might as well introduce the background basics of the setting, so it would be a good idea if you designed the adventure for that setting of yours.

After playing that short adventure, the players will have a feeling for the system, will know basic information as to the setting, and will be able to decide for themselves, as to their characters, whether they want to
a) create their own character starting from zero,
b) tell you "I want a warrior" and accept what you come up with,
c) work with you on the halfway solution, i.e., start from a template and customize it.