You could do a number of things that would benefit you in some way. Biochem is very useful all around with the ability to make medpacks, stims and adrenals. Synthweaving would allow you to make armor pieces. Artificing would allow you to make hilts for your lightsaber and enhancements for all your orange gear. Cybertech would allow you to craft mods for your gear and armorings for your armor. Armstech and armormech are not very useful, only really allowing for crafting of gear for your followers. One more option is to only grab gathering and mission crew skills, which would actually be my recommendation if this is your first character. Crafting can eat up a LOT of credits, which you won't have a surplus of starting out. Gathering resources for a second (or third) character to have them get a jump start on crafting isn't a bad idea, as there are plenty of ways to get gear while levelling. That being said, if you have to go into crafting for whatever reason, I would recommend biochem if you are going to be an assassin tank, cybertech or artificer if otherwise. biochem will allow you to make your own stims and adrenals, and reusable medpacks, VERY nice for a tank as you will eat through them. Artificing and cybertech both allow you to make two different modifications for orange gear, and either one is fine.