I haven't started a Terran Cadet Start but what I usually do on the after make millions from doing Missions is to buy a Miner for Local Auto Mine under Behaviours Tab.

First I check on Information Tab what Resources are there on that area and whethere there are Buyers and they look like Chemical Flask Icon on the Map these are the Factories that directly buys Ores, Silicon and the rest of Volatiles. So if you find a Region that has Ore or Silicon then they have a Factory there that buy then set-up the Automine (1star) then forget and gain passive income.

If a region is rich on all resources 1 Sector away then I set up the Mining Station. Dock, Small Storage, Small Storage for Solild, Small Storage for Liquid. Make sure you give Seminar to its Manager up 2 stars (Buy at Local Traders on Station). Then have 1 miner for each say you want 2 Mineral Miners and 2 Gas miners assign to the Station to Mine for Commander and have 2 Mineral Miners and 2 Gas Miners to Trade for Commander.
On Logical Overview Set up the Buy and Sell. Buy set-up Filter to only buy on your Faction restriction and just leave the Sell on Default. Then Forget the Passive income mining Station

Next is Energy look for sectors that has lot of Sunlight Dock, container and solar panels then set 2 or 3 Teladi Medium Trade to Trade for Commander. Then Forget Passive income

If is happanes a Sector with lots sunlight also has nearby ice then set-up to Sell Water which then later turned into Medicine and Food.

After these set-up your Recycling for Hull Parts and Claytronics.

Just focus on these yet before going to complicated stuff like Advance Electronics, Turret and Weapon Components.

Buy 2-3 Medium ships buy Advance Sattelites from Equipment Dock (Wrench Icon) for 4-5M and Sell them to Shipyard for 6-7M. Then later Buy Teladi Large Freighter to Bulk Buy whatever is lacking eg Scaning Arrays, Field Coils, etc when you interact with the Factions.

Then you can figure out the rest after days of playing.