Factory recipes are no more. Rock is useless now.
Neutral stations are all 'decayed.' They can be build-blocked or salvaged but only give decayed circuit and metal blocks, these are recycled at 10:1 into new circuit and metal blocks that can be used in factories to make simple modules like power gen and storage, thrusters, salvage, factory, basic hull and more.
More complex modules require ore/ crystal mined from planets or asteroids. When these resources are refined you also get good new circuit and metal blocks as well - enough that I have not yet needed to supplement supply with recycled blocks from decayed stations.
So start with mining some stuff. Refine it in your micro crafter page of the inventory to get the circuit and metal blocks.
Second you make a basic factory - also from in the inventory. You want to first produce a power gen blocks from this factory (don't place it on a decayed station or it will decay immediately ) if you have none due to a survival start you have to use the power supply pistol to run the factory for the first block.
With the factory powered produce power gen and salvager blocks and grow your salvager as you continue to mine. Make the standard and advanced factories in the basic factory for access to all the other blocks. You may want to make some factory enhancers to speed up production as you mine faster and faster.
Selling the basic stuff is good but soon you want to move up to using the standard factories. These take one type of the refined ore/ crystal and one or the other of the circuit/ metal blocks to make weapons, support systems and some other stuff.
Advanced armor hull, shields, turret docks, AI, cloak, overdrive, warp and similar modules require the advanced factory and significant amount of a crystal and an ore to make one module.
There is no way to make an infinite factory loop anymore. You need to keep up the resource supply. There are at least a variety of filters on storage so you can make factory systems that distribute stuff automatically. Factories also only run while the sector is loaded.
There is also pirate stations. They are typically found in void space, I've only been in between the galaxies spiral arms not above or below the galactic plane. They are still easy with weak turrets. The loot drops in the chests can be disappointing but pirate stations are not decayed and can be build-blocked for valuable hull/ glass still. However they are typically quite far from spawn.
The mining is a little tedious once you really get it going though. At least if you claim a system with a faction block you get a 6x bonus to mining in that sector. If you can get away with mining in someone else's sector you will get a 3x bonus there.
The universe is indeed vast. My home galaxy, basically empty but considered crowded. Some ambitious faction has already build a warp gate network (the blue/ white line) with many intermediate stations 'down' to the galaxy below indicated only by it's wormhole network map (purple/ white lines, white end indicates destination).