Hi, generally speaking there would be two ways to go about this:
(1) Disable things that use up performance if you don’t need them (i.e. Lumen, Virtual Shadow Maps, Volumentric Clouds, Ray Tracing, Nanite as long as you’re not using very high poly meshes; although Nanite may perform better if you have lots of high poly meshes, so you could try both options and compare). And avoid common performance sinks like lots of shadowed lights and lots of overdraw (foliage).
(2) Get insights into what takes up performance → stat unit to make sure you’re GPU bound, then GPU profiler to get a quick overview and RenderDoc to get an in depth view. Then based on the profiling info, optimize what takes up the most time.
Also to check how much performance those textures and materials take up, you could write a script that executes on BeginPlay and then swaps out all the materials to a simple one.