isn't your instructor supposed to provide you with tips for that?
i have some kickboxing experience from my earlier years... as far as stance, i think key is finding a balance, both literally and figuratively... because on one hand, you have to be light on your feet (and so you're on the balls of your feet, with a slight bounce) and yet you have to try to keep your center of gravity low so both that your strikes are more powerful (because ultimately your strike force is generated by pushing off the floor, aka newton's 3rd law of motion) and so that you can absorb strikes better...
i'll spare you my specific advice for striking and kicking because i'm sure your instructor will explain everything in good detail and it will come with experience, naturally... one thing i'll mention for you to keep in mind is newton's second law of motion - the force you generate is a product of mass
and acceleration... so, for maximum effectiveness, when striking you need to use your strength + speed... so train both!!
(in addition to the fact that telegraphing your strikes means your opponent will have the time to block or elude them, anyway)
also i'm sure you already know, but flexibility is a huge issue, so stretch well...