The MYX is a commercial-grade bike used in thousands of gyms globally and is the most accommodating to all shapes and sizes, so we're pretty sure you'll be pleased with the seat!
It's normal for new riders to feel a bit of discomfort initially when riding any bike. Most find that in time, with regular riding, it goes away. Some also find benefit from cushioned seat covers or padded shorts.
That said, you can replace the seat if you so chose. Please note that any damage to the bike hardware voids the warranty and precludes you from being eligible to return.