I've been lurking for a while, watching amazing pictures of impressive ships, and suddently i asked to mayself "how is it possible ?".
Are you playing "legit", i mean, from scratch in a kind of survival mode, like in Minecraft when you start a game for the first time ? Are you building ships in creative mode and then copy them to survival mode ? Are you actually playing the game, or only building stuff ?
I mostly don't like creative modes in any similar games, and i mostly don't like multiplayer, but that said, i wonder how i should play Starmade. I want to love it, but so far i've never played for more than a couple of hours every few weeks or months.
I do both. For single-player I use admin commands and build huge ships. For multi-player servers, I play "legit" - I can't use commands to fill my inventory with goodies, I don't abuse the blueprint system (e.g. saving a cube of shields and buying it several times), etc.
For the latest version of the game, it can be a struggle. My advice is to start by trying to get the blocks you need for a simple/tiny ship equipped with a jump drive, plus a faction control block, an undeathator, some storage blocks, and a build block if you can manage to afford it. Find a nice planet somewhere (use the galaxy map!), claim it with the faction block and set it as your faction home. This makes it a safe place to store your stuff (and return to if/when you die).
Next, you need salvagers and power generators (and misc. stuff like thrusters, etc). Do whatever you can (including mining your own planet) to raise cash for those. Now, if you salvage planets or asteroids you get ores/crystals. Keep those (do not sell them) because you will need them for later (to get anywhere without cheating, you must setup a factory and you will need the ores/crystals for manufacturing). You will also get things like dirt/sand/rock. Sell them if you can, but they're not worth much and shops fill up fast. Abandoned stations aren't much use either (they only give you scrap now, which can help for manufacturing simple items, but they're not fast profit like they used to be).
What this mostly means is that, until you've got a factory setup, the main source of income is pirates (I wouldn't recommend attacking trading guild ships). This means both pirate ships (which can be hard to find) and pirate stations (which are easy to find). Both of these will attack back, and will do enough damage to kill a small/weak beginner ship. That's why you need the power generators - to power your cloaking/jamming; so you can gather the resources you need for a larger ship without getting wiped out by pirates and losing your current ship.
Note: The alternative to cloaking is shield blocks. These are hard to manufacture (the ores you need are very rare) and they're the first thing that are sold out at shops on multi-player servers. You also need a more expensive ship if you're not relying on stealth (more blocks, more thrust, "standard or better" hulls, etc); which is easy enough after you've got your factory working, but not so easy before then.
As a rough estimate (it depends on server config, etc); only 1 pirate in 7 will drop loot and that loot is random, and it's probably going to take 2 hours of flying around just to find some pirates (they don't show up on scanners). Alternatively, if you can salvage an entire pirate station there's a 100% chance of getting a lot of blocks, and you can easily make 8 million credits per station (and keep the stuff you want to keep), and there's loot in the station's chests for even more credits/blocks (typically more "bonus loot" than you get from pirate ships). More importantly, it doesn't take too long to build your ship's salvagers up, so that you can salvage an entire pirate station in about 15 minutes; and walk away with about 20 million credits every 15 minutes. That's far faster profit than searching around hoping to stumble on a group of pirate ships.
Of course it's probably going to take a while to build up your ship (so you can salvage more, faster), and get a basic factory started. Once you reach that stage you can start salvaging asteroids and planets for ores/crystals; and making things (e.g. ship cores) to sell to shops in exchange for the harder to manufacture blocks; and keep doing that until you've got enough to build a decent ship. The other thing I'd be doing is building a better home base, with (e.g.) docking areas large enough for a decent ship, an item sorting system, a much larger factory, etc.
Note: Different people have different ideas about how big a decent ship is; but I'd just keep salvaging asteroids/planets/pirate stations until you've got enough for a 100K+ ship. Your perma-cloaking salvager should be fine for almost everything until then. 
