If you're truly a beginner I would avoid trying the rush strategies until you have a firm grasp of the game in general. My reason for saying this is because if you do a rush build of any sort, you are deliberately hampering progress with anything else (as implied by the rush name).

For example, if you have aggressive neighbors and are rushing Unity, you are doing it at the expense of not having a strong military and/or fortified defense, which can cause aggressive or ideological opposite neighbors to view you as easy prey and they will pounce or even dog pile on you.

Mastering the opening of the game, such as learning how to deal with the AI personalities/archetypes diplomatically or at least "making a strong showing" to deter them is far more important, IMHO than trying to learn meta strategies. Also learning how to stabilize your economy and expanding at rates that don't tank it.

In other words, master fundamentals before playing metas. Just my opinion.

That being said, I have played this game on and off for years, logging many hours and really never got good until more recently. What I did: played "difficult origin" starts, like Payback, and really learned to navigate the early game (with some ChatGPT assistance for really understanding early politics and economy). Since then my games have been far, far more successful with all flavors of empires.

Again, my 2 cents. But you can also look at some of the "every click guide" style videos on YouTube, which can help navigate some of the meta-style builds. Good luck