"'If you are there, will YOU help me?" Remember that conditionals have two parts: the if-clause and the main clause. You cannot remove the subject (you) from the main clause. It's possible to use "If you are there, would you help me?", but this is what we call a mixed conditional. Here, we have a strong possibility (1st conditional) but an uncertain result (2nd conditional). To be honest, we native speakers use these mixed conditionals "as-needed" and even then it's pretty uncommon to do so. Just read, listen and communicate, then you'll realise when and where you can use a mixed conditional.