Don't ask simplistic cliche questions.
That is a trait often associated with someone who is not ready to do the necessary work from the ground up.
Just look at all the answers you received. Trying to make sense of them all will drive you round the bend.
Many answers are just opinions which aren't true or real (and can't ever be either), as they are just what each person has encountered/experienced. This is why they are called opinions and not facts.
Its just like someone saying "Product A was great", but when you try Product A,, you find it is terrible. It doesn't mean Product A wasn't great for the other person. Just not you.
The best thing I can suggest to you is keep your money in your pocket for at least 6 months.
In the meantime, read, read, read and keep reading all you can find about this business and avoid any hype and hysteria about some trend/extension/industry, as you are likely to get your fingers burnt following such "advice" and "recommendations" from unknown and unaccountable people.
Domain names are particularly susceptible to hype/hysteria as registering a domain name is very low cost, so the risk to take a gamble on something seems small.
But buying one such domain can lead to you buying two, then three, or five, ten, fifty...Domain forums are a key source of this hype/hysteria and most hype/hysteria centers on new extensions and/or real or perceived trends, like the nonsense around the defective concept of AI.
Domain names are also subject to theft and scams and criminality is not foreign to ostensibly big and/or trusted names. Sloppy and non-existent security is also a factor that exists with some registrars and marketplaces.
One significant problem you will discover is that because the domain name market is a mature market, you won't find the treasures to register that were available in the 1990s, or in the early 2000s. Those days are long, long gone. So this may mean that you will have to buy worthwhile domains in the secondary market or at auctions.
Ignore all extensions that are not .com.
This is because they are all junk/worthless (for domain investors) and invented by the domain industry just to extract more money for nothing from idiot/simpleton registrants and then sold on to even bigger idiots/simpletons, sometimes for eye watering prices.
The only except to this point is if you are targeting a specific country-relevant name and register a name with a cctld.
There is one area that still has potential and that is registering made-up words. This takes a lot more work and also creativity than trying to find domains with dictionary words (very hard), or putting together 2 or 3 dictionary words.
There are many examples of businesses that are well known and which have made-up words as their company name. Made-up words are less likely to have an existing trademark but you need to check on this before buying any available name.
Tread carefully and make sure you fully understand why you are going to register any name when you are ready to. Ask yourself if you were a suitable business, would you buy the name you want to register?
KEEP PAPER RECORDS OF EVERY EMAIL AND/OR CHAT RELATING TO ANY DOMAIN NAME YOU BUY/SELL, IN ADDITION TO KEEPING ALL INVOICES/RECEIPTS AND SUPPORT TICKETS.
