Generally manufactures use a soft spring and firm damping to make it seem firmer. You usually soften the damping and put
a firmer spring on. You need to see how much the bike sags with your weight on it to tell if the spring is soft or firm.
The front is probably a damper fork. You would have to measure the size and see if someone like Racetech had something
that could be used on that size to allow for some tuning.
Small bikes and scooters do not get much support from the aftermarket as you might have to pay 1/4 - 1/3 the cost of the bike to get proper suspension.
If you have progressive springs changing them to straight rate would help. If the springs need to be firmer cutting approx.
10% of the length off and rebending the end then making new spacers will help. The bike will ride higher in the stroke so will absorb bigger hits.