I think Coinbase, with Coinbase Pro, is a good choice for a newbie on crypto.

If you simply buy or sell in the spot trading only what you invest is at risk. You probably get the risk alert when you move on margin trading or others working with leverage, as it happens to me on Binance. But as far as I know you can lose what you invest, due to the high volatility and the leverage. For further info I suggest you to read some tutorials on your exchange, otherwise stick with the spot trading.

This kind of trading is pure gambling. I've experienced on my skin, some Binance newly listed currencies increased their value by almost 1100%, while others fall by 100% or more. The low-risk strategy is to buy the asset on other exchanges when the listing is announced, while the high-risk strategy is to buy the asset right after is listed on Binance. I definitly prefer the High-risk one 

If you have a good amount of money to invest it can become a good income, but it'll require a lot of time to learn how to read properly a chart and how to trade properly. Not a task for everyone.