xvntnc

Honestly I'd hold on to most of it until you get a feel for the game. Spend a bit of it on slots (though you can sell most of the early weapons once you master them, they aren't that good), and once you start getting weapons and frames you like orokin catalysts / orokin reactors. Then, once you know what you hate doing, spend it to avoid doing that thing to farm something.

If you want to splurge on something early, buy the prime version of a frame you like (or like the look of) off of http://warframe.market. Prime frames honestly aren't that much better than the regular versions, but they're tradeable, and being the best version of what they are it's easy to justify investing forma and orokin reactors in them. Note that you'll still have to build the frame, so make sure you have or can get the materials required for the blueprint.

The other advantage of using loadouts like this is that you can change them directly from the nav screen.

It's worth mentioning that the poe fandom wiki still ranks higher on Google for most queries than poewiki.net, even though the fandom wiki is an unmaintained ad riddled mess. The new developer supported wiki is nice, but since fandom refuse to take down the old wiki there's a lot of outdated info that ranks highly in search results.

Baruuk is pretty much my favorite frame to play in Circuit. Add in all the melee buffs and it's just gigantic red crits everywhere at ludicrous speeds.