So, I tried my hand at Void Opal mining in my Python, and I netted about 35 million credits in about 2 hours worth of effort. Not bad for my first time out. Now that I am getting the hang if it, I think I can start making some real money with this.
Time to fill up the bank account and get Trade Elite.
You probably noticed already but:
When I started mining, I went outside the bubble because I thought that would be more calm and quiet, meaning less stressful learning. However you don't have to do that. The pirates scan you when you arrive at the hotspot, nag that you have no cargo and leave. Then you're "safe" until you FSD again. Now I'm starting to take out the pirates as well, just to gather engineering materials.
Normally I try to get roughly 100 T of opals per trip in a Conda (~2 hours). You can speed things up by bringing more collector limpet controllers. Notice that a size 3 means 2 limpets, while a size 5 only gives you 3. Therefore sometimes two size 3 are better than one size 5 (depending on free slots).
Two abrasion blasters makes it easier to hit the sticky opals. Also consider the mounting of the abrasion blasters. Put them in slots that are as easy to aim with as possible. Up front and centered is best.
The most important thing though, is learning to identify potential cores. That just takes practice, and speed things up considerably.
Keep going, and you'll become a billionair very quickly.
Edit: Just tried a mining trip to see the CR per hour. The ring I chose turned out to be rather bright, which I personally dislike. Also there were a lot of fissured asteroids not containing opals, and my only abrasion blaster was placed under the ship (a no go, as I mentioned. Do as I say, not as I do

). Finally I chose the selling station before leaving, and when I got there the price had dropped to ~700K per ton, so I had to go to another station to get a proper selling price. Still, all in all including everything from finding a ring to selling the opals took 2 hours and I got 130 mill CR, or 65 mill per hour. The trip was not optimal, so 100 mill per hour is well within reach.
I prefer the rings furthest from the star. Less action and less light. It might take an extra minute to get there, but that minute is well invested.