When Aden was a newborn she had to sleep with me because I was too paranoid to actually fall asleep if she wasn't right there in front of my face!
I slept on my side, and she slept on her back or on her side with her face near my face. I did use a pillow and one blanket, and it was never a problem. I barely even moved when I slept, sometimes I would roll over onto my back but I was always aware of what I was doing. I usually had her swaddled in a blanket as well.
Whenever she slept with me she would sleep for 4 hours, nurse, go back to sleep for another 4 hours, etc. When we tried to put her in a pack n play or bassinet...not so much. She might sleep for like 2 hours and then start fussing.
Just do whatever feels natural and comfortable to you! And don't worry too much, co sleeping is perfectly safe