Yes, always check the easy stuff first. Since the bike was covered up, it may also have suffered corrosion from moisture trapped under the conver at places like the ground wire and even nain fuse. I assume your main fuse has a good connection. When you have a charged up battery properly connected, do any lights work? You know, oil pressure, neutral, headlight, etc. If not, make sure you have a good fuse and the ignition switch and is on. Also, I assume if you have lights and no spark, the kill switch is not off.