Hey and welcome to AA
Allaboutfish is right, the test strips are a complete waste of cash. The liquid kits (most recommended is API's master kit) are more pricey but work out better value (both in monetary terms and fish health) in the long term. As for the peas, boil them and shell them and then just give a little, there should be no evidence of food after a minute. Remove any that is leftover so that it doesn't fester at the bottom.