Basically, you did it. Sounds like you did a single-temperature infusion mash with no sparge (sometimes confusingly called 'single sparge'?). But, your process sounds kinda wonky, here's some ways you could improve this:
- Add the hot water first and stir in the grain. This helps get all the grain exposed to water without clumping.
- 65-68C is a good mash temperature, but note that when you add 10 pounds of grain at room temp, it's going to cool down your water. The initial water you use should be hotter than 65C to compensate for that. I'm a dummy so I just use this tool to help me figure out everything about the water when mashing:https://www.brewtoad.com/tools/mash-water-calculator
- Use a thermometer to make sure the mash stays at 65C or whatever, not casually splashing it. If you're mashing in a decent insulating cooler with a lid on, you might not need to add any hot water to maintain the temperature, as long as you hit the right temp in the first place.
- "Siphoned the extract into my boiling water" Does this mean you diluted the wort out of your mash tun with straight water pre-boil? That's pretty inefficient. Any water that you want to use should be used to help get all the sugars you can out of your grain. That means, 1. you should probably add more water to your mash because 2gal/10lbs sounds way too thick, and 2. you should probably sparge. There are a few different ways to sparge, 'batch sparge' is probably the simplest way to go, but basically it just means rinsing out all the sugars you can from the grain. I'll let you look up how you want to accomplish that with whatever equipment you have.
- You crushed the grain first, right?