Aside from the other good advice already given, I'll add the following-
Learn the difference between quality and junk. By "junk" I mean knives that could actually endanger your fingers. There are quite a lot of people on this forum with a lot of experience with both quality knives and junk knives, listen to their advice.
Listening to the advice of others is valuable, but in the end it's your money, your needs, and your preferences that matter, so buy what YOU like, not what others tell you you should like. Don't buy a knife just because it's popular, or because someone on Youtube says it's awesome.
Before you buy a knife, do thorough research on it. Ask on this forum about it. I'm not saying that you should let others make up your mind, but the members here might have experience with a particular knife, and provide pros and cons that could help in your decision.
Also, and just as important as anything else, ask about the vendor selling the knife. Sadly there are a lot of unscrupulous people in the knife world (not here at Bladeforums) who sell counterfeit knives (cheap imitations of quality knives) and you don't want to get burned. Just as the members here have extensive experience with knives, they also have experience BUYING knives.