Most people just need a paring knife and a chef's knife.
https://www.nytimes.com/wirecutter/reviews/best-paring-knife/
I love the cheap Victoronix recommended here.
And for chef's knifes:
https://www.nytimes.com/wirecutter/reviews/the-best-chefs-knife-for-most-cooks/
But the most important thing is to get a sharpener and use it. A cheap, just sharpened knife will work better than the best knife that hasn't been sharpened in a long time, though good knives need sharpening less often.
https://www.nytimes.com/wirecutter/reviews/best-knife-sharpening-tool/ has recommendations, but really the important thing is to use it regularly - the specific sharpener doesn't matter as much.