You do need to be pedaling to shift.
You might want to make a little excel spreadsheet to look at the gear ratios of each gear combo.
Theres always overlap in possible gear ratios when shifting on the front gear. I have a MTB that
Ill sometimes shift up (bigger gear) on the front, then immediately down (smaller gear) on the back
to acheive the smoothest increase in gearing.

Also-
You may want to take it in to a shop for a tuneup to make sure everything is adjusted properly