To start your first campaign you should choose the offer and the ad format you want to run. Then you should choose the tartgeting you are going to use for your campaign - geo, OS, connection type, etc.
After that you should prepair creatives for the offer - pre-landing page, landing page, video for VAST format, etc. Please, remember that it's much better to use the native language for your country targeting. Then you should add funds to your account. You can start your first campaign as soon as the money will appear on your ballance.