How do I know which SSD is suitable for my notebook?

I have an HP Pavilion DV-7 6032sg (is about 8-9 years old) and wanted to replace the hard drive. The exchange is very fast, because you do not have to screw up something big. Actually, I wanted to buy the Samsung 860 Evo and install it, but in a forum I read that it may be that the SSD can be connected, but still can't develop their full potential and it does not make sense, therefore to buy such an expensive SSD. Now I wanted to know how to find out whether there's a bottleneck with the respective SSD or not?

May I help you:

You will not notice a speed difference between all SSDs in normal work, since even the slowest of these works is so fast that limits anything else.

Exception: One second at startup, but rather less.

So I should rather look for cheaper SSDs?