I'd test if the system correctly recognises hardware encoders and decoders on your graphics card.
You can do this by running mpv media player with the following command:

mpv --hwdec=nvdec your_yideo_name.mp4

If you then press I while the video is playing inside of MPV and it says "nvdec" next to "Video:" and "h264" or "h265", it works.

If this works and you are still experiencing problems with game streaming from Sunshine, then you have misconfigured Sunshine.

If it does not say that, or it refuses to start because it can't find NVdec, you need to install the (older) proprietary Nvidia drivers as you have an older 10 generation card, which aren't supported by the integrated free software drivers that most distros use to talk to nvidia GPUs.

For the future, I mean this in a very kind way: Please be more specific and concise when describing your problems. From your question, I don't know if you mean that you want to optimise your system in general, if you have trouble using it as a host for game streaming, so you run Sunshine on it and play the game on another device, or if you want to use it as a client for game streaming, so another machine is running the heavy game and you're just streaming it to the "low-spec" machine. Reason is we're strangers on the internet. We don't know what's going on with your system because we don't have access to it. We don't even know what your system looks like. So you need to be very detailed and very precise with what you want to accomplish and what problems you currently have.

Edit: typo.