Contango is the situation where the current futures price is greater than the current spot price for the underlying asset.
If you want to long in the future market, you need to roll over your contract. It basically means that you have to buy future and sell current which will incur losses.
The original future market is backwardation market, means the future price is below spot price. It is because the big seller willing to lock in the price at the premium. However, due to the high trading activities in recent decades, the traditional backwardation market is gone.