"Comment ça va?" is a familiar approach to ask someone how they are doing.
It is usually answered by "très bien" which means - very well -
"bien" - well -
"Comme ci, comme ça" meaning - so so -
"mal" - not well -
"très mal" - not at all well -
Even if you know very little else of the French language at the moment, I am sure whoever you are talking to, will be appreciative of the effort.