Much of this thread excuses Frontier's poor design for new and casual players as a "feature" for having fun. Here is the reality.
No game disrespects your time more than Elite. If you are a casual player, this creates a huge challenge mid-game, made even more difficult by ongoing nerfs to the credits necessary to buy, outfit, insure, and replace third-tier ships. This can make it very difficult for casual players to move beyond second tier ships. You are more or less a second class citizens in Frontier’s eyes.
If you are hardcore, you can get through the time, credit, and reputation gating. If you are a casual there is a strategy to deal with this.
First the learning curve is steep, so be patient with yourself.
Second, focus on working up to the best second tier ships you can. These do much of what the third tier ships do. Focus on working up to an AspX (for transport and exploration), a Python (for trading and mining), and an FDL (for combat). If the beta version of the T9 comes to fruition, that will be best for trading. In addition, engineer your ships. Engineering in Elite is a form of crafting that allows you to improve your ships components. Once engineered, these ships miss out on very little.
This does not mean you’ll never get a third tier ship (e.g. Anaconda, Cutter, Corvette), but unless you focus on credits from the get-go, it will take a very long time.
Third, get outside the starter bubble and avoid Open. Elite has an ongoing problem with griefers. Frontier may address this issue through a karma mechanic slated for a future update. For now, new pilots should never log into Open until they are well outside the starter system and its bubble. If you enjoy meeting other pilots, you should also join the private group Mobius straight away. Mobius is the largest pve group in Elite and one that rivals the size of Open.
Fourth, avoid pvp for now. I love pvp. But in Elite, combat is an expensive time and credit sink even for the hard-core. If you do pvp as a casual player, be prepared to see your credit reserves dwindle rapidly.
Fifth, join one of the great wings out there. Mobius (a wing as well as a private group) is one and is located in the Azrael system. AEDC is another and found in Wolf 406. You can find a list of wings on INARA. There is strength and wisdom in numbers. They will help you thrive.
Sixth, grab credit and reputation making opportunities whenever they arise. The mission system is one of Frontier’s most poorly designed and implemented mechanic. It neither generates enough missions nor offers adequate rewards. Yet because it was poorly designed, it routinely produces unexpected opportunities. Frontier eventually nerfs these, but in the meantime they can be lucrative.
In the past rare-trading, smuggling, long-distance transport, skimmer, combat zone, and passenger missions are some of the examples that fit this bill. All have been nerfed into the ground. As of this writing, there is no credit meta to help you bypass Frontier’s gating. But keep an eye on the official forum and reddit for these to (hopefully) turn up.
For all missions, mode switching between Open, Solo, and a Private group helps you stack multiple missions for efficiency sake. Don’t grind until your eyes bleed. But do look for ways to be efficient with your time.
Seventh, Frontier left out the info and social tools needed in Elite. So third parties developed a wealth of tools you cannot do without. Visit Elite Dangerous Codex for a comprehensive list of all the amazing tools out there. Of special note is EDDB, ED MarketConnector, INARA, Coriolis, EDBearing, and Wavescanner. Search on the web, the forums, reddit, and youtube.
In all of this, remember that there is no endgame. Elite was envisioned as a virtual world in space (a cosmos) which fuses gaming with simulation elements. So you won't find tight narrative mission arcs guiding you to the conclusion or win, as there is none.
Good speed.