PeaceLoveSmile - As I understand what you are doing, you are measuring the conductance (the reciprocal of resistance, that is, G=1/R) of the different fluids, orange juice and sports drinks using a milliameter and a 9 volt battery. Both types of liquids will conduct current - orange juice because of the ionic nature of the citric acid in water, and commercial sports drinks because of their inherent 'electrolyte' qualities based on their contents of mineral salts, carbohydrates and other chemical compounds. I don't know what the hypothesis of your project is, so I'm not sure how this will correlate into your experiment.
The issue of translating units is somewhat simpler. The basic equation for resistance is R=E/I, where the unit of resistance, R, is an Ohm, E is a Volt and I is an Ampere. For conductance, the formula is inverse, G=I/E, where G, the unit of conductance, is the Mho (Ohm backwards), or now known as the Siemen, R is the resistance in Ohms. To translate your readings from microamps to amperes, divide by 1,000,000. To translate milliamps to amperes, divide by 1,000. Your calculator is using 'scientific notation' and is expressing 0.7 microamperes divided by 1,000,000 to be 7x10 to the -7th power, or .0000007 amperes. If you haven't studied scientific notation, just use the old math with all the zeros and decimal point. Hope this helps.