New to the Beta myself, not too keen on trading.
Found out that the bst way to make some credits (if your not up to taking out NPC pirates in the resource extraction site in LP-98-132) is take courier and/or small delivery missions from the board.
Best way is to try and accept mor then one mission to a target system (often the board might have a couple of missions to the same system, even to the same location). Never travel empty! even if the mission pays ~1k credits.
Dont be afraid to take on 11k haul missions (usually transporting up to 4 tons of gold/silver). This way the credits roll in fast, and you will be able to upgrade or buy a new ship.
Regards,