On the main screen, you will see "Search Contracts" on top, where you can type anything in the Search bar and it will search for contracts. You can filter the results by type: Forex, Futures, Options, All.
To Browse for contracts, in the "Search Contracts" section, you will see these buttons: Futures, Options. Click on one of them and start browsing contracts.
For Futures, as you browse, you will be shown the contracts for the front month. You can select other expiry dates by clicking on the line that says "Front Month".
For Options, in the Option Chain screen, look for the side arrows at the top to change the months.