Rhino is a very powerful warframe, and can carry you through most content on the star chart essentially with just Roar and Iron Skin. Unfortunately, using Rhino as a new player tends to end up with using his abilities as a crutch and learning the actual systems of the game too late. I cautiously recommend Rhino.

Vauban is a king of crowd control, but he's an energy-hungry frame, and as a new player your most reliable source of energy will be the Eximus enemies that ignore your crowd control. I recommend Vauban later on.

Nekros is kind of a one trick pony, but his trick is very good in a game where you farm drops. If your survivability isn't a factor, I would recommend Nekros now.

All 3 are fantastic frames, but can really begin to shine when you have access to more powerful, specific mods (Corrupted mods from the dragon key vaults on Deimos, Augment mods from the 6 syndicates) and systems later in the game (Helminth for swapping abilities, arcanes for bonus effects). Nekros's survival issues, Vauban's energy hunger, and Rhino's harsh fall-off in very high level content can all be solved with setups that you won't quite have yet.

Volt himself is pretty good for clearing all the starter content, I would recommend Nekros for the farming utility.

You might want to consider farming for a Volt Prime if you have a source of plat already

Honestly, while you're new to the game, just pick up the frame that looks the coolest to you.

At low levels (anything up to 30), all frames can run most if not all missions. Later on you'll find that certain frames specialize in certain things, like Rhino for leveling new weapons quickly or Nekros for farming certain resources.

Rhino is a safe bet due to his defensive and offensive abilities so usually people recommend him. If you want something more than just combat though, Nekros is good for resource farm and Vauban is a big CC (crowd control) beast that can pull in enemies and group them for easier killing or objective defense.

You can't really go wrong with any of them and sooner or later you'll probably have them all, so I'd say just go with the one that appeals the most to you.

If you go for Nekros, you might want to consider grabbing his Despoil Augment from Perrin Sequence/Red Veil to deal with his energy management.

Shield of Shadows is another useful augment for reducing damage taken and for status immunity.

Nekros is superb for ressource farming. I would go for it

Go for Revenant. Practically immortal disregard to enemy lvl, has crowd control and cool mobility. Scales incredibly well to late game. Best frame for endurance runs period. Can protect all team with mesmer shield augument. No need to get prime version as there is no difference. Relatively low invesment to achieve perfection.

Luckily most of the normal frames aren't too hard get or to reaccuire. I'd recommend playing around with all of them as much as your inventory allows.

However it's always nice to keep a Tank and a Nuke om standby.

Personally I used Harrow for everything for the longest time. He and thick mommy Hildryn carried my scrub ass through most of the Steel Path Star-chart.

But then I discovered the Sith Lord of warframes... Mag. She's an absolute powerhouse and therefor my current go-to for almost everything.

Doesn't matter, in no time at all you'll be getting a new frame and levelling it to 30 a couple of times (because of forma) in the same day (absent the delay for build times, but that isn't time where you need to do anything) All the frames can do standard star chart stuff

But if I was prioritising warframes I'd ensure I had an area CC Warframe like Vauban, Khora, Nova, etc as they are useful for defense/mobile defense/excavation