Perform the lowest space combat missions in the Fleet mission console in your ship. The lower ones will be done without a geared ship. These will still give you fleet comms which then enable you to slow upgrade your ship to do better and better in combat until you start using the custom made and Grade 7 quality gear.
I'm pretty sure that the only ship upgrades you can get with fleet comms are the Power Conversion Module (level 25), Electronic Warfare Pod (level 35), EMP Generator (level 45) and Proton Torpedos (level 50)
There are actually 42 other ship upgrades that can be bought for credits at the vendor and the gtn.