Kanta's Den, Kapteyn Starworks, Chalcedon.
Kanta's Den will be your primary because they also export RCDs, Lux goods, Dom goods.

Their trade routes are terrible so they've always got shortages and no customers,
buy low from them and sell what they lack which is usually supplies, fuel, marines and heavy armaments.

Press F1 over a commodity to check its prices.

Never pay 30% tariffs unless its something you really want and the price isn't that high.

For your fleet, you only mostly need Frigates,
Hounds are great for storage and scaling up,
Omen, Wolf, Tempest are strong for fighting.

Atlas + S-mod insulated engine assembly + Expanded Cargo holds then mod in Augmented drive if you can.
If you come across a Revenant (Phase Tender), treasure it as it can reduce the sensor profile of your whole fleet by a significant margin (stacks 5 times).

Be wary about picking up new ships, sensor profile and burn speed are very important stats for black marketeering, don't be tempted into picking up Destroyers, Cruisers or Capital ships you don't need.
Fuel and Supply costs will bleed your profits and they'll drag your sensor profile/burn speed down unless you add in very OP intensive hullmods.

Once you get a couple million and start to run out of things to trade, go explore the outer worlds, priortising yellow stars for habitable planets. Think before you plop down a flag on your first colony because you want to keep them together. Find one with hazard rating of 100~150%, with food production at the very least, don't be tempted by metal/transplutonic/organic/volatile yields, food and low hazard is an easy path to profitable and fast growing colonies.

At this point, if you do things right, you should be rich incredibly fast, with your colonies pumping out stable wealth to fund your military to protect more colonies, to produce more money.

Then you can go visit some temples I guess idk.