The Basics- Destiny

That's because you've not played past the Prologue.

Time to hide your Game's Played list again.

Because the guiy who paid money for an Ninja Turtle Outfit for his avatar and believed that you could not pass beyond level 20 in "Destiny" said so.

I look forwards to you taking a break from the Forums to compose many angry worded letters to any gaming website that has the audacity to cross you and heap further praise upon this great game.

Just a heads up...Destiny's PVP is broken as hell. Get a Shotgun, Suros Regime and a Fusion rifle. You can dominate with the starter gun in PVP. Seriously. You already have the better shoot & loot: Borderlands 2 & the Preseq.

So on to your actual questions:

Okay, In Destiny, a Strike you get teamed up with 2 other randoms, unless you already have a 3 man team put together. It's basically the boss-fight for each planet. There's a "Weekly" Strike you can do solo, but it's been tweaked to make it nearly impossible
to solo it, but it's possible. You have to bring your own team to the Weekly. You can get different levels of gear and upgrade materials. You'll do these to get from level 20 to level 27/28-ish. Then it's on to the raid-

Raids you have to gather 6 people for a team. No matchmaking, you have to do it yourself (sucks). It's a 2 or 3 part mission where you have to fight a ridiculously OP boss that can teleport you around, get the relic and some other stuff. This will get you
the currently best gear...eventually.

Money: You get Glimmer from pretty much anything. That's your main money, it's plentiful and after a few days of playing is pretty useless. Then there's marks. Once you hit level 20, you get Vanguard marks from doing Patrol missions, Bounties, Strike Playlist,Daily
Heroic & Weekly Strikes ( I think from the Nightfall strikes too) and farming materials. Crucible marks come from playing the PVP part. (ew) You get 2 if you lose, 3 if you win. You can earn 100 Vanguard & 100 Crucible Marks per week. (resets on Tuesdays).
These you can use to buy Legendary weapons & Armor from the various Vanguards and if you want Factions. You may also receive these weapons/armor from playing Crucible and Random drops from Strikes.

Strange Coins & Motes of light- Strange coins you need to buy from Xur, he sells Exotic weapons & armor and a couple of Sparrow upgrades. You can get them from Weekly strikes, and random drops. Motes of light show up every time you would have leveled up
after lvl 20. Sometimes they show up as random drops too.

Now now, if they guy wants to waste his money who are we to dissuade him? Seriously though rent it or get a better game to utilize your new Gold membership.

What story? That's the problem there aint one...