So, in all of my 46 years I have never used public transportation.

I'm needing a way to get downtown that won't cost me a ton of money and someone suggested I could take an RTD bus down there.

I know there's a park and ride off of 120th just west of I-25. But once I get there how do I know which bus to get on and how do I pay? I mean do I need cash and exact change or can I use my debit card? I don't need some sort of "bus pass", do I?

Thanks.