2012 Plug-in Prius at 120K: dealer service recs vs what do I REALLY need?

Hello and thank you for any guidance. I have a 2012 plug-in prius that just turned over 120k miles. I know when I go into the dealership on Friday they're going to tell me I need all SORTS of things and I don't know how to distinguish between 'let's get the uninformed older woman to buy every service whether the car needs it or not" and "I really need to do this." After reading online, the things that seem to be important to do at this point and that I have not done yet are (1) spark plugs, (2) transaxle fluid and maybe (3) engine coolant/hybrid system coolant." For the last few oil changes, all I've elected to do is to rotate the tires. Can someone who knows what they're talking about please advise me? I appreciate any help in making informed choices here....