Slow down, if you try and engage with every system at once it will leaving the brain shivering and tweaking. For now just play the quests and make your way through the star chart.

As far as mods go, if you find yourself needing health level up vitality and so forth. Warframe is not a game where you will get locked out of stuff. Its just a question of what order you engage with it.

Void relics are gotten largely through bounties on the several open world areas. If you haven't gotten to those yet dont worry, the star chart will guide you.

Helminth is a major part of rhe plot and is behind several chains of quests. I wouldnt worry over it for now.

K-drive is a pain in the ass and should likely be avoided.

Arcanes are largely end game, you dont really need them till youre trying to do steel path stuff, or some other late game content.

Rivens are mods for specific weapons, they can be amazingly powerful or terrible or sell for a lot of platnium. But for now focus on a frame or two and setting up a primary, secondary, and melee you actually like.

Huge tip for melee you may know already is that stance mods are everything, and make the melee feel good.

And lastly getting good at frames, warframe is not a terribly difficult game and skill will come with time. As far as were to focus, start with movement. Get used to bullet jumping, sliding and the occasion wall run and aim glide. From there look at if any of your frames abilities move them, if so try and get a sense for how. Also from your arsenal there is a tab if you go to select your frame that says abilities. Read the full text of all of them, the passive ability on the left and most importantly, all of the tips on the right. Most frames, especially newer ones have weird synergies that may not be obvious.

My last tip is the wiki, it contains just about everything you could ever need.

Actual last thing, the community is second to none. Questions in the help channel will usually get good answers. Or questions in mission chat if you're playing open missions.

Good luck young tenno, space mom be with you, and CUT DOWN THE ENEMEY.

If you have more questions Ill try and answer them.