I feel like Im not making money at all. 12 hours of playing and I've barely scrapped 40k together, which was mostly from random wanted guys. The problem is lack of fuel for me and being unable to track pirates. I don't quite understand the trading part to earn enough money either.
Buy from a place that has a high supply of something and sell to a place that has a high demand. Trading is honestly pretty straight forward.
It's probably worth elaborating on this some, because while the principle here is dead simple (buy low, sell high), actually executing it is more difficult in Elite than maybe it should be.
First: if you don't mind using automated tools and don't think of it as cheating (some people do, some people don't; it's your playthrough, do what feels right), you can use things like
Slopey's BPC Tool or
the Elite Trading Tool. Slopey's is the most automated in that it runs alongside the game and can actually figure out what system you're in and tell you what are good trading runs near you, based on crowdsourced data. The Elite Trading Tool is similar, only you have to tell it what your location is.
But let's say you have no interest in using these tools. Slopey's in particular is actually kind of slow on startup, and besides, even if you have no ethical qualms with using these tools, you might still want to know how to figure this stuff out using only in-universe tools.
To figure out what a good trading run should be, you'll need to know two things: what commodities locally are in oversupply, and what systems and stations are willing to buy said commodities. So first, dock at a station if you haven't already. Make sure the station has a commodities market! Many smaller outposts don't have a market, which means you can't trade openly there. (You might be able to do black market stuff there but that's strictly advanced material that we'll skip.) You can find out if a station has a commodities market or not by opening the System Map and clicking on the station in question; you'll see a list of services in the left pane. While you're at it, note the list of imports and exports. That'll give you a decent idea of what that station is selling and buying.
Once docked at the station, you can see all its market data. Pay close attention to the column marked "Supply" and look for any entries that say "Med" or "High." That means supply of those commodities is relatively high, which means they'll be selling at below market rates. BEFORE YOU BUY, THOUGH, make sure you can actually sell those commodities somewhere close! For that, you'll need the Galaxy Map and some trade data.
The Galaxy Map can show you the general flow of goods in the region, though unfortunately I find it rather lacking for reasons I'll explain later. To see trade routes in the Galaxy Map, switch to the View tab and click the View Trade Routes checkbox. You should hopefully see a bunch of coloured lines emanating from your current system, and perhaps lines from any other nearby systems you've visited in the past day.
Remember that list of commodities your station has a ton of? Turn off all the trade route lines by hitting the Clear button, then turn back on one of the commodities your station has a lot of. See where the lines go. Those systems are buying that commodity. Stock up at your current station and fly your ass over there!
One caveat: the map can't tell you what those systems are paying for that commodity, so even though the map is showing trades in the right direction, you might fly a bunch of goods over to that system only to discover they're actually paying less for that commodity than you originally bought them for. Such is the life of a lone space trader sometimes. Try somewhere else. From everything I know so far, there is no good way to know in advance the buy/sell prices in other systems besides keeping track yourself. This might even be an intentional move on Frontier's part, given that they've told the people behind the trading tools above not to scrape price data from the Elite client (which is why they all rely on crowdsourced data).
Another caveat you should watch out for if you're new: some goods are only legal at certain stations, and
they are not marked as such. Tobacco is a good example: in some stations you'll see them listed under Legal Drugs. But they're actually illegal in what seems like 90% of all stations. Until you have a better handle of what's legal where, try to stay away from anything that sounds even remotely sketchy. This includes drugs, weapons, slaves and toxic waste. (I personally don't have a great handle on what's legal where, so if my list is too broad, apologies.)
There's much more to say about trading but this post is already way too long. Good luck!