I just purchased CC3 and have been using it for a few hours, but the main reason I got it was to create some modern soldiers for a FPS game I am creating. But I don't really know how to get started.
I would like to model a small detachment of marines (5-10 soldiers) each slightly different than the other, I have not had much experience in character design and could really use some help getting started and figuring out what I need.

Does CC3 have any assets for creating soldiers? And can I include my own custom clothing and armor?

Are there any other programs I should get to make this task easier?

Hello, this may interest you.  I've bought it and it 's really enough for all action military scene you want

https://www.reallusion.com/ContentStore/Character-Creator/Pack/UN_TaskForce-Uniforms/default.html