Hi, I'm a user here, but can answer your question. I see Dario answered your question, but he is a busy guy and gave you a quick answer. I'm retired, so am not as pressed for time as Dario, so I can give you a little more detailed answer, because there is a lot more to CoinTracking than manual entry, but that's always a way to go.
Hopefully, you have downloaded the free trial so you can see what I'm referring to. On the Menu Bar, there is a link called "Enter Coins", from there you can pick your poison. If you only have a few trades to put in, pick "Overview & Manual Entry". Let's assume you have a lot of transactions to put in. There is not currently a way to automatically load the trades from gatehub so it will have to be a semi-manual effort. To do the import to CoinTracking, you have to be able to download some sort of transaction file from gatehub. If you can do that, it's just a question of manipulating that file to get the data into the right places in CoinTracking. CoinTracking will try to figure out what the columns represent by the header name, but you can fix that before the import. CoinTracking even gives you a preview of what the import will look like before you tell it to proceed. if you have ever imported an address book from one application to another, the process is much the same. A good thing about Cointracking is that you can make a backup of your database before you do anything, so if you create a mess on your first attempt, you can just restore from the backup and start again.
So the best way to be sure this answer works for you is to download the free version, download a transaction file from gatehub (a csv will do fine). Then just see how easy/hard the whole process will be for you.
I hope this helps!
Steve