I had never driven a motorbike before I got my Symba in 2010, and found shifting pretty tricky/darned near impossible. Part of the difficulty is that shifting is dependent upon the size/shape of your foot - I have a relatively short foot, and a very high instep. The shift-lever is adjustable/movable - and, then move it (i.e. the front toe-part) down 1 or 2 clicks...and give that a try. Someone with a larger/longer foot might need to move the lever BACK 1 or 2 clicks. It made a huge difference for me.
I'm pretty sure you'll find additional answers by searching the SYMBA site...