Ultimately, if you want to make money with crypto you have a couple of options. The easiest thing to do is to build a diversified portfolio of carefully selected coins and then to simply wait a couple of years. However, this is not the most effective way to make mad money. If you want to truly crush it at crypto, you need access to truly knowledgable people.
There's a lot of ins and outs which can get confusing in arbitrage trading. We won't go into the technicals of why futures contracts trade at a premium to spot price. You can read a full explanation here. If it's not of interest to you, all you need to know is that there's a tendency, the further out in time the futures contract expires, for the premium to spot to be higher and higher in nominal percentage terms.