Oasis of the Seas was the first cruise ship DW & I went on. Not just first Royal ship, first cruise. It was almost 10 years ago (2013), and there's a link to the trip report in my signature. I'm sure they've changed things since we sailed her, but if you want a report from a "first timer", you might want to read it.
We later took our kids on Freedom of the Seas (actually twice) and find that Freedom worked better for us. I will say, while Oasis is big with a lot of people, we didn't really notice the people except certain times (following a show and muster drill).
We're booked on Mariner of the Seas for July of 22 and interested in what she has to offer.
Thank you! I’ll take a look - be great to get first timers view, it’s been that long since we’ve cruised I feel a first timer!