I found sleeping on my left side to be the most comfortable back then, and it really helped with digestion too. Now that I'm breastfeeding, I still prefer side sleeping, so it's a good habit to build!
Honestly, sleeping on the left side with ten pillows stuffed around me like a fortress was the only way I survived! Just get comfortable, don't worry too much about rolling over in sleep.
When I had terrible morning sickness, sleeping slightly elevated on my left side helped with both nausea and acid reflux. Try using a wedge pillow, it really helps to soothe the stomach.
Sleeping on your left side is the absolute best position because it improves blood flow to the baby. Just buy a pregnancy pillow, it makes side sleeping way easier.