I traded both. I started with stocks (invested and then traded) and was successful.
My psychology was not yet developed for the markets though and forex is a different beast. Stocks were easier for me. Liquidity was never an issue, even though I moved the market with my orders hahah.
My phone is going crazy right now so I can’t test the app. What I can tell you is:
Some reasons why EUR/USD will go up (you buy or go long for the purposes of this example):
-EUR fundamentals is more bullish than USD and USD is neutral.
-EUR is neutral/weak but USD is weaker.
-EUR and USD have both bullish fundamentals but EUR is stronger
So in the example you presented, basically if USD is weaker than EUR, EUR/USD goes up. That’s why you buy when you believe the USD is weaker. When you go long (buy) you’re essentially buying Euros and selling USD (to explain to you as simply as I can).
Now, when you throw the app colors in the mix, when the color is red that means USD is stronger than EUR in that instance only. That doesn’t mean you should sell EURUSD if the app color is red and buy when it is green. There’s more to it than that.
Don’t panic, just observe the charts and give it time. If all else fails, try the stock market. More money in forex, that’s true, but that doesn’t mean you cant make serious money in stocks.
Since you are fooling with CMC, maybe you are in NZ or Australia. In that case there will be less money (liquidity) than compared to U.S. stocks–so you could stay up late trading U.S. stocks or you could learn to trade the ASX index.
I’m sure you have a ton of questions by now 
Hope this makes sense. Gotta go fix my phone.
P.S. Trading has a higher difficulty than investing. Especially is you day trade.