Oscillator setting is controlled through the CONFIG Register. The only Internal Oscillator option available is 4 MHz.

The PIC12F508 has no analog capabilities, only 1 Timer (Timer0), less-than-minimal memory, was introduced in 2009... It may be an acceptable choice if you only need to toggle an LED. To actually do any real work, it's about useless.

I don't know if you have at least PBP3.0, but there are an abundance of newer designs that may cost less, and will certainly do much more. For the 8-pin application, a good universal choice is the PIC16F18313. Don't let the "PIC16F" fool you, it is an 8-pin MCU. Grab a data sheet and have a look. I think you'll like what it can do, and it's cheap.