Lighting Setup for Exterior and Exterior+Interior?

I tried yesterday playing with almost all the relatable settings in the foliage static mesh window and directional light parameters besides skylight. I also replaced the HDRI backdrop with a static skybox. l also set the sun to static. With static skylight and movable sun, I have got the best results yet. But without the grass blending in nicely and giving 60+ fps, I can’t move forward.

Did you model the grass yourself in this scene or bought from the marketplace. And what about lights? Are they static or dynamic?