Hi
rushlock and welcome to the forum!
I agree with you that there isn't a single "starting walkthrough" with this game, although there are a lot of really good guides on overall strategy. As you are aware, ST is one of these games that is extremely deep in terms of complexity, and no two games are exactly the same. So providing a walkthrough were we say
Turn 1 - go to planet x (urban area)
Turn 2 - go to Palace
Turn 3 - Complete first contract (deliver message)
Turn 4 - go back to planet urban area
Turn 5 - Visit Spice hall, check for rumors
Turn 6 - 2nd rumor is a Metal Shortage rumor - use $3000 of your cash to buy 8 units of metals from the exchange. Also buy 10 units of Water Fuel
Turn 7 - Fly 5 units left, and 3 units south of your current position, and go to planet urban area to sell metals at profit ...
As you can understand, this can't work in a random complex sandbox. Your start location will be slightly different (especially depending on your faction), your cash and experience will be different based on difficulty levels. The rumors are different for each game (based on planet levels) and then you have random conflicts and encounters to factor in.
Instead, we provide initial guidance on what you should be doing in the early parts of the game ...
After completing your first mission, invest any XP earned into Pilot skill - in fact, boost your pilot skill to 15 as quickly as you can.
Check for rumors on each urban area you go to - look at any shortage rumors and if the goods in question are non-restrictive, and the destination is reasonably close (within 10-15 AU), then buy goods matching the shortage and take the goods to the appropriate planet.
If you want to do some contracts for money and XP, then don't buy a trade permit straight away. Doing contracts without a trade permit usually mean the contracts will be cheaper, but they will be less dangerous. Often that means "deliver x to y" type contracts.
There are more specific activities for different classes, and also different skills/attributes to focus on depending on the style of captain you play. ...
For example - a gunbunny captain (who hates boarding) will focus heavily on Pilot to keep pilot to at least 200% of level. Boost Tactics whenever you find you aren't hitting targets during combat. Boost stealth if you are getting hit and/or unable to evade encounters and/or finding you are getting too many encounters.
A boarder captain should, on the other hand, focus on Pilot + Warrior and boost Strength because as of today, strength doesn't affect your level - some captains have 800 strength and are still only level 5 ...
The starting point on the forum for help is this thread
startradersrpg.proboards.com/thread/4267/consolidated-list-information-players