How do I meditate if I don’t know what comfortable position to put myself in

Try different positions for different mediations. In the morning when I wake I’m usually laying down so I do my first meditation while laying in bed. In the afternoon I’m usually sitting so I’ll do some breathing exercises, or if I go for a walk I’ll do a walking meditation. When I’m feeling anxious and need to feel grounded I sit on the floor in cross-cross applesauce position.
Find what works best for you. Using guided meditations helped me resolve my confusions in getting started with meditating, so keep practicing until you find your rhythm.