49 cc 4 stroke semi manual

i have a 49 cc 4 stroke semi manual pocket bike. changing gear is very challengeing for me. changing from one gear to the next do i need to let go of the throttle before changing the gear with my left foot? do i really need to be on neutral before going to 1st gear? please help

ive rode quite a few different 4spd bikes and you should let off the gas to shift but you can usually get a 2nd gear wheelie if you stay in it, although the downside is that ive ripped the rear sprocket bolts out of two bikes now doing that, so i recommend letting off the gas. and there are two types of 4spds, one that shifts both ways like a big bike and one that is a rotary shift. the up and down gearbox its fine to go from 2nd to 1st but the rotary shift you have to shift all the way around thru 4th to get back to N then to 1st