Disneyland Paris is easy, book a Hotel, tickets and have a vague plan. And you'll be fine.
As Disneyland Paris isn't a destination on its own, unlike WDW, you don't really have specialized travel agents for DLP.
Tip 1: via Disneyland Paris you can only book package deals. These will always include park tickets for all days you are on site. If you want less park days, you can book a room only by calling, or via a platform, like booking.com.
This rarely saves a huge amount of money.
Tip 2: At the moment there are still not a lot of offers (post covid), but if there are: play around with the different country websites. It is possible that the UK has different offers than France.
Tip 3: Do not worry about language. The entire park is bilingual.
Tip 4: when you come from the airport, there are 3 ways to get to the park: Bus, train and private transport. There are pros and cons to all. It depends on you what would fit best.
That's it for now, don't make it too complicated, you can do this yourself