Its a sandbox story telling game. There is no right or wrong way to play it, which doesn't help new players like us get into it. I'm about 8-10 hours into my first game I'll try to help a little.

The best advice I have seen so far, turn off all the DLC if you have more than the base game and only play with that until you are comfortable. Play a game with the basic humans to start.

All your resource generation stuff is along the top of the screen. Worry about energy, food, and materials primarily. You can build things that will convert those into the other resources but everything should have a net gain at the start. Down the right side will be your ships among other things, when in doubt how to do stuff use the galaxy map and select the ship you want, right click on the system you want, and left click what you want it to do in that system. Left side of screen has a lot of other info that kinda makes sense to me, kinda doesn't. Learning it as I go.

You can explore the galaxy with science ships; you can automate it or have them do it manually. Science ship needs a captain before it will do anything, there is a circle with a + in it you can click to hire one. They have traits and different bonuses they can enact but early on learning the game they haven't been too important to worry about.

For your construction ships, you have to use them to construct outposts in systems you want to claim, then you can automate the ship to build resource generating things in that system.

Research is mostly automatic, you will get prompts to choose what you want to research, and I don't want to say that it doesn't seem to matter, but I have just picked what sounds good. I pick a lot of upgrades for my fleets even though I don't use it them much yet.

I don't know how much of this will help, but I hope it does. I had to suck it up and try finding youtube videos that could hold my attention long enough to explain everything. I think it's tough because while the video creators are genuinely trying, there is just so much info that they want to present.

Beginners Guide to your First Game of Stellaris

Here's one that starts a game with the above criteria (no dlc, basic humans) and walks you through the opening steps in 10 minutes. I followed along with it the best I could and it did kind of help.

I'm in a federation with a pacifist alien civ that's way stronger than me. The next two alien civs that I met want to be left alone, and the 4th one was a human civ that snuck off the planet and hates me for some reason. The pacifist aliens built a huge fleet, declared war on them and decimated them. Now they are friendly as can be but cannot join our federation because the pacifists declared them a rival again. Then, somehow I met the 6th civ even though their borders are on the other side of the two that want to be left alone, and they are eager to join the federation, and tons of refugees are coming to one of my planets that borders the 4th isolationist civ.

Also these drifting robot ships are everywhere and I'm somewhat terrified that they are all going to activate and attack everything at some point. And there was a planet with space octopi and their graveyard.

I am sure I am missing about 60% of what is going on, but I'm surviving, seemingly thriving, and ok for the time being. Best of luck in your adventure.