if i were starting a character on one of the orphan servers, i'd certainly restart on a more populated server.
you certainly don't "need" groups to finish your jedi knight. i finished leveling a jedi knight just a couple of weeks ago without help.
there are some datacrons that require 2 people (1 each on taris, quesh and hoth), so unless you can scare up someone on your server you won't complete your datacrons. moving to another server will be more fun though if you like groups and will be a definite plus for what little level 50 stuff there is to do. you best restart before you get higher and invest more time in your jedi.
if you want to stick with it and rely on bioware to let you move to another server in a few months then make sure you keep you jedi and kira geared up as much as possible. do all the quests in each area for xp and gear drops and use your crafting to help you. i used biochem with my knight and the constant stream of stims and medpacs sure helped me over some of the big bosses. the reusable stims and medpacs are real nice.