Hi,
there are so many cryptos and I find it hard to identify the ones where I should have a closer look.
Obviously one can find cryptos e.g. by listening to shilling on Reddit. But I'm looking for more professional sources like YouTube channels, free/ paid Telegram/Discord groups and so on. What do you use?
You can use the forum itself, this is the best place to find information about crypto. To find a good currency requires a lot of patience because the currency market is now quite diversified. You need to learn more graph analysis skills.