Does anyone know how you can create a 3d model character for your game, using model images like this?
With a 3D modeling software like Blender (free).
However, if you have zero experience with 3d modeling, then you’ll probably take quite a few months or even more before being able to model, texture and animate something like with that quality and details.
I don’t do it, this is way above my 3D modeling skills. A simple workflow to get a humanoid character is to download a free model (you’ll find some at cgtrader.com), make some changes in a 3D modeling software, upload it to Mixamo, auto-rig it, download the animations and import them to UE4, together with the skeleton. This may not result in high-quality characters and animations, but it does not need high skills in a 3D modeling software.
I recently made this with characters I created in MakeHuman for a low-poly crowd. They’re not realistic and the animations are not perfect, but it’s enough for a crowd of people in some meters distance.