There are many different websites you can use to get a hold of 3d models (if you want better made once you probably will have to pay). There are however many good free assets as well. Try to search for “low poly axe” on the unreal market place for example. Sketchfab is also very good.
If you want to create the models yourself your best bet is probably Blender. It’s free and one of the best 3D softwares out there currently.