Use lower resolution for example Use Stretched 1024x768 or 1280x1024 resolution if you have low fps (Also it depends from your Max resolution so if you have max resolution as 1366x768 then use 1024x768 same for 1280x1024 = For 1080P screens but if it still runs terrible use 1024x768 or even 800x600)
Remove textures and effects There is shittion of tutorials which can show you that also you can remove sun, moon etc,
Close all background programs
Reinstall windows if you have shitton of useless data (backup useful one) eventually you should downgrade to older windows versions like windows 7 as you will always get few frames and more responsible system
Upgrade your PC/Laptop if you can check parts compatibility etc And if you have older laptop you can probably change CPU and Ram
Computer>Properties>Advanced Settings>Advanced>Performance>adjust to get best performance
Upgrade your drivers
Scan your pc for any viruses or etc
Before you will change visual settings ima show screenshots how it looks on my desktop vs my custom settings, also don't use programs such as razer cortex or etc
Also very unproffesional video which shows performance gain from removing textures and resolution https://youtu.be/ox8GC7C9YQ0