If i am trying to create a module, for example, that simply generates different voltages and spits them out of a CV jack to carry the signal to another eurorack module, how do i know what power is required, if its from either the positive, negative or 5v. Super noob on this topic.
This the most important part, context to understand your question! Everyone starts as a beginner. But if you ask only a narrow tech question, at best we can only give you the specific answer. With an understanding of what you're really trying to accomplish, we can actually help.
In this case, you'll probably power the Teensy from 5V. Teensy LC & 3.x run on 3.3V power, but they have a VIN pin for 5V and then they create 3.3V.
To create a CV output, you can use either Teensy's DAC pin or you can add a fancy DAC chip which has better performance than Teensy's built in DAC. Probably the best example of the fancy DAC route is the Ornament and Crime module, which is fully open source. It's complex, but that's a good place to look for a well designed solution to generate the best quality CV output.
For a cheaper approach using the built in DAC pin, which gives either 0 to 3.3V or 0 to 1.2V (with lower noise and better stability), you'd add an opamp circuit to boost Teensy's lower voltage DAC signal to the higher voltage used for CV. I'm not a eurorack expert, but my understanding is at least a few different ranges like -5V to +5V, 0 to +5V, and 0 to +8V are used for CV, so the very first step would be to figure out exactly which of those you need.
There are lots of other forums more specific to DIY eurorack projects, though not so specific for Teensy. Whereever you post, remember we can help you much more if you put some extra effort into your question to give us understanding & context of what you're really trying to accomplish. Narrow tech questions are easy, but unless you're an expert (and maybe not even then) it's very difficult to know exactly what to ask. Best to explain your goals.
