A pocket knife is a daily tool. It opens packages, cuts rope, splits an apple, cleans a fish, scores a line in wood. The person who carries the right pocket knife every day uses it more than any other tool they own. The person who carries the wrong one leaves it in a drawer.
The steel is where you start. High carbon steel -- the kind used by Case, Buck, and the German knife makers -- takes a sharper edge than stainless steel and is easier to resharpen on a whetstone. The tradeoff is that high carbon steel can rust if left wet. Stainless steel holds up in wet conditions but requires more work to achieve and maintain a truly sharp edge. For a general-purpose pocket knife used in dry conditions: high carbon. For a fishing or boating knife: stainless.
The Case designation 'CV' stands for Chrome Vanadium, a high carbon steel alloy that has been used in cutting tools for over a century. CV steel takes an edge sharp enough to shave with and holds that edge through a day of normal use. It can be resharpened to factory condition on a leather strop or a fine whetstone. Buck uses 420HC -- a high-carbon stainless that splits the difference between pure high carbon and standard stainless. Both are correct choices for different uses.
The pattern determines function. A stockman (three blades: clip, spey, and sheepfoot) is the most versatile traditional pattern. The clip blade does general cutting; the spey blade does detail work; the sheepfoot blade cuts without a point, which is useful for cutting toward the hand without risk. A trapper (two long blades: clip and spey) is the most popular Case pattern for general daily carry -- useful, balanced, and long enough to actually grip. A penknife is smaller and lighter; right for a shirt pocket but not for real work.
Handle material is about feel and longevity. Jigged bone is the classic Case material -- natural bone with a texture cut into the surface for grip. It ages beautifully, developing color and character over years of use. Stag (deer antler) is the premium traditional handle material. Rosewood and ebony provide a smooth, dense feel. Celluloid (the synthetic handle material on many Case patterns) holds color well and is durable. Avoid plastic handles that are hollow -- they are lighter and feel cheaper because they are.
Buy a knife from a company that has been making them for at least a hundred years. Case has been in Bradford, Pennsylvania since 1889. Buck has been in Post Falls, Idaho since the 1940s. The institutional knowledge of steel selection, heat treatment, and grinding that produces a knife worth carrying is accumulated over generations. A new knife company making good knives is theoretically possible. The companies with century-long track records are not theoretical.