Make it think many times and you'll just make it research those coins you want for, relying others opinion isn't quite good for you.
I don't think so. If you have $500, then you can choose 5 coins only and only use $100 for investing. But you need to search profitable coins that will be difficult to find unless you have skills to analyze. Maybe after you can get those coins, you can just hold and don't trade the coins because you know that you are not good at trading and you are afraid to get lost. Besides that, you can choose those 5 coins in the top 5 coins from coinmarketcap and don't look for the other coins.
Holding your preferred coins is a very wise idea, since we're still on the mode of bearish market that took so long. Probably some of panic and weak handed traders seem to be more afraid right now, but for those long term hodlers it's a normal thing for them. They won't mind those bad sides and good sides, because all they long and expect for crypto is the increasing pumps at an unpredicatable time. We can't predict in an accurate ways, but picking the right coins depends on how smart you are.