Without deep research, you can't estimate the potential of a certain coin soberly.
And I always monitor different news websites like CoinDesk or CoinTelegraph, and CoinMarketCap to see the situation on the market with my own eyes.

Also, I like to read various price predictions from experts or just random forumers. Can't say that I truly believe in what people are saying on the market, but it's interesting for me to learn about their considerations on certain topics or coins, and then I compare that with what I observe in real life.
And yes, before investing in some coin you should identify if it's profitable or not. But also keep in mind your security — there are lots of scams. So, double check any information you see on the Web.

Different people define a good exchange in different ways. It can be security, liquidity, fiat currency support, payment methods, verification requirement or its omission, trading and transaction fees, … the list goes on. Old crypto exchanges like CEX are popular among traders because the platform has been gaining its reputation for several years, it’s not ideal though. I also use it for BTC/EUR trading because it’s convenient for me — https://cex.io/btc-eur. But I don’t like tedious registration. Although I realize that the registration is a part of security measures adopted by the exchange to ensure traders’ protection.
The idea of creating a crypto exchange isn’t new today. Much as you would try, you won’t create the ideal platform that would suit everyone. IMO, to create a good crypto exchange you need your platform to solve the issue of crypto trading in another new way that will endure more value for your future users.