This video is an overview of the types of cables and connectors you’ll find when using classic game consoles. The first half of this video is an overview of each of those analog signals, while the second half goes into some RGB SCART technical details – You can skip that if you’re not interested in the details, but it’s a good clarification as to why some RGB SCART cables can be “dangerous” and why buying quality cables is important.
Here’s links to help you on your next steps. I definitely recommend watching the RetroTINK Mini and RAD2x video if you’d like more info on using flat-panel TV’s with classic consoles:
Links to cables for each console: https://www.retrorgb.com/systems.html
Inexpensive Retro Gaming Scalers: https://www.retrorgb.com/retrotink2x.html
Quality HDMI plug & play cables: https://www.retrorgb.com/rad2x.html
How to check the components in your SCART cables: https://youtu.be/Z3sE3uk5kPU