Doctor questions

Hi ladies,

I was hoping to get more helpful info/recs from my doctor at my baby’s 4 month check (we did it early bc going out of town) but feel more confused. He’s almost 4 months (born 1 month early). Some things she shared - keep trying pacifier (he doesn’t like them I thought that was ok?), intro foods at 5 months and doesn’t matter kind (I thought 6 months and should as intro veggies first?), and no help about my concerns that he prefers to sleep on rock n play and difficult to transition to bassinet. I am worried about his hips and neck but she was more concerned about the small pillow attachment and sids. He also had a rough evening after his shots and we were given no warning! Thoughts on these things?