I get your situation, it's a confusing game sometimes. There is a wiki to the game that covers a great deal of information. Somethings you need to know, and even somethings you don't. I'll provide the link at the bottom.
Let's start with crafting: The crafting system all starts with the gathering of materials. Smithing for example, that would be finding Metals (iron is the starting one, the weakest) randomly generated around the map or buying them from guild stores, find them and click on the and it will collect the metal. Once you have sufficient metal, bring it to a forge (in towns, should be marked on the map though it might be a hassle to find) and start crafting. You'll need race specific material as well though, so be sure to get some of those too; they can be bought for a pretty cheep price from a blacksmith that is, as far as I know, at every single forge in cities, they can also be found in chests, barrels, boxes, some corpses, etc. Once you have these items, bring them to the forge and start smithing. You'll need to choose your metal, how many you want to put in, your race specific material, and a trait (optional). the metal you choose determines the damage of the weapon you're making, as well as the armor rating for the armor you're making. This is also the reason for choosing how many ingots to put in as each metal type has a range of level. For an example, Iron is used for making gear level 1 through 13 (I'm using 13 as an example, I really don't remember it's max level). If you character exceeds level 13, you'll want to use the next level of metal, I believe that's steel. In order to use the next level of metal, you'll need to put a point in the proper smithing perk. Which brings me to briefly answer another question: no, there is no level cap. When you reach level 50 (I believe), you start getting things called, "Veteran Levels," for the use of using higher ranked gear and getting more perks. Anyway, one of the perks you can get is the ability to have a hireling that will gather resources for you (get the perk and you'll have them, no need to find one to hire), they'll send you a message once every real time day with resources attached, if your going for crafting I'd highly recommend getting this perk (it's in all of the crafting skills, not just smithing). But back to crafting itself: Each item has it's own minimum number of materials requirement, some items you can get away with putting just 3 ingots in, while others you might have to put 5 in. Select the metal, select the amount, next it to select your race specific material. If you chose, say, a Khajiit, you'll ONLY be allowed to use the Khajiit specific material, Moonstone, unless you find (or buy from a guild store) a book called, Race Motif, that will teach your character how to craft other race styles. This step is purely cosmetic. Next, your trait. Traits come from gems that you can either find, buy from guild stores, or retrieve from weapons that have traits in them buy, "researching" the trait. This will consume the item and take real-time hours to complete. A lot of hours. Unless you have a specific perk, you can only research one item at a time from different crafting styles (smithing, woodworking, etc.) this includes both the armor and weapon, if your researching one you can't research the other unless you have that perk I mentioned. Lastly, upgrading. You can upgrade item that you don't have equipped by using certain items (they'll tell you in the description of the item that they are used for upgrading, you won't miss them). Upgrading has a CHANCE to work, the more upgrading items you put in, the more likely you are to successfully upgrade the item. Fail, and the item will be destroyed, along with the upgrade items. Metals, race materials, upgrade items, trait crystals, and experience CAN all be gained by breaking an item down. If you plan on building up smithing, I'd recommend keeping any and all metal weapons and armor you pick up, if you can, and breaking them down when you get back to town. This info applies to Smithing, Woodworking, and Clothemaking or whatever they call that last one. Either way, the principle is the same. You don't have to train all of them, choose which one you will use the most, or all. It's up to you.
As for money making: Sell, sell, sell. Anything and everything pretty much. Whatever you can, ESPECIALLY items that say the sell for more to merchants, I don't know if you can learn that trait, but if you can, do. After you initially learn it, sell all the other ones you find. Even if they're metal and you're trying to build up smithing, these are the exception to the, "break down everything," rule. Other than that, I'm not too sure. I never found a better way.
As for DLC, try the crown store.
That's all the help I can provide for now. Leave me a comment if you want to know more, I'll try to be your personal guide, though I must warn you my knowledge is limited due to the fact that I don't really play anymore. I've been on the Elder Scrolls wagon since Morrowind, but I was very disappointed in ESO since it's really a completely different game in and Elder Scrolls skin. Anywho, I hoped this helped! Have fun crafting! ^_^
Website: http://elderscrolls.wikia.com/wiki/The_Elder_Scrolls_Wiki