sounds more like it doesn't disengage properly (clutch), is it better if you pump the clutch pedal a few times? if yes might want to look at the master/slave/fluid for the clutch hydraulics, if not could be a pressure plate issue.
try what Jeff said with shifting in 2nd and then move to 1st, if that works better could be a syncro but 1st is actually not as common with this problem as 2nd and 3rd as far as I know.