It would be easier to translate the sentences that contain these words in order for you to understand it in your own cases. However, here are some examples:
"Doch war ich noch da als du mich angerufen hast" - "Yes, I was still there when you called me"
In this (colloquial) sentence, 'doch' is not easily translated, but it's something along the lines of 'yes', after someone for instance has asked the person whether they were still at the party when they were called.
"Du bist doch noch ein Mitglied, nicht wahr?" - "You are still a member, right?"
In that sentence, 'doch' is emphasizing the question "..right?" - again not easily translated.
In both example cases, 'noch' means still. Please post some example questions if you are still unsure - these words are not always easily translated.