PSA - Account Security - It's a thing - You should look at this thing.

[Sigma-Astra]

Don't bother with making an overly complex password, just make something you can remember unique to this game.

You and Mhaeric are both correct that four random words is a good strategy for a password, but it's also suggested that you should still use uppercase, lowercase, numbers, and/or symbols with the four random words.

My fiance works in the IT field specifically, these are things that he himself suggested to me from his knowledge in the field that he's been working in for at least 10 years. I've heard horror stories of passwords he'd find for a business server that hosts all of their emails when he was called in to fix a problem with it, and their server password was "12345". I think he facepalmed so hard and immediately corrected them because that's a huge security problem for a business. xD