For early game as a new player, you don't necessarily need to focus on sustainable. Tap an oil well near your base and start refining it. Use the Minium stone to get diamonds (for refineries) and obsidian (hardened glass to make Redstone Energy Cells).
I had actually never used oil before my most recent DW20 world, but I'm quite pleased with it. I tapped one small oil well near my base and it's been more than enough to carry me through to mid game. I have one small Railcraft tank half full of oil, another full of fuel (576 buckets), and more fuel sitting in the refinery, engines, and the liquiducts between them. This oil well is going to last me a long time.
As a new player to the modpack, I will warn you that combustion engines are very dangerous if not properly planned for. I can go into more detail if you'd like to take this route.