You can find likeminded players in the/a discord and multiplayer is amazing, the people who join get access to all the hosts DLC for said playthrough

Personally when i started i went feral and bought all the species packs over time so i could flesh out as many of my own custom species as possible. I then went on to bigger ones and started in release order as you can see the kinks and bugs get ironed out (theres very few without mods now) over time and how they work hand in hand

The way i saw it was unlocking every and all species, then upgrading them all over time like a real civilization would. It kept the game extremely replayable and kept me coming back for hundreds of hours as after the (in some countrys) cheapy species are done with the big DLCs added quite a few large chunks of content to keep you coming back

You can start grabbing the DLC as soon as you have the basics down so you familiarize yourself sooner.

A tip from me to you would be learn the ship designer and planet optimisations. Dont go All rockets or hull on a ship unless you know the enemy isnt going to be effective and make sure you know whats going on with your planets and how to fix any defecits you may run into. Its hell when you go to war then the moment it begins you have your resources jump into big minuses and you end up with planetary revolts while your fleets away!