For spring planting after last frost, that means up to 3 months growing time indoors. Otherwise, sow direct outdoors in summer to early autumn.
Pansy seed propagation indoors is easy. Start with a high-quality seed mix. Fill the plant trays and sow the pansy seeds into the tray, making sure that the seed comes into good contact with the soil. Cover them so that they are in complete darkness until they germinate in around 14 days. Introduce light and let them grow, plant outside when danger of frost has passed.