The best thing i can suggest is to go BACK to the trainer and see if you can learn more schematics. New ones will open up to you once you get to a certain crafting level.
Also, some of the missions skills, like UWT and slicing will provide schematics you can learn - also the GTN you can buy schematics. If you've learned all of the blue recipes, then you will get a tool tip that says "no research available" or something like that. Some crew skills, such as cybertech, the percent of learning a purple earpiece from a blue one os 10 percent, so be prepared to get a lot of fails. You're right though, it does cost credits initially. It's a lot easier once you have a rich higher level character to help you out with money.
As far as selling is concerned, look at what price things are going for on the market and under cut by 1 credit
If the items are grey you wont increase your crafting level, that's why you have to learn new schematics from the trainer on the fleet or on a planet, if they have trainers on that planet, or get them from missions or the GTN.
Hope I could help you out a bit.