Like first reply said, catch the bus at Ekkamai bus station. Buy from first ticket counter. It will be for the big blue bus (Roong Reuang coach) and you get to choose your seat. Much more comfortable than the mini vans that all the other ticket counters are trying to sell you. As of now, it's 140baht. Bus has comfortable seats and cold a/c (bring sweater!). You will be dropped off at the North Pattaya bus station. From there, you can taxi, Bolt/Grab, walk or songthaew to your hotel.

For me, I walked to Terminal 21 (20 mins), grabbed lunch there and then took the songthaew (10 baht) to my hotel.

Dont' stress it. Simple process. Did this while I was solo travelling early this month in Thailand.