How do I dissolve sodium oleate in distilled water
A product information by Sigma-Aldrich, a chemical supplier, cites Merck Index regarding the solubility of sodium oleate.  And states "It is 
also soluble in water (approximately 100 mg/ml)", in other words, 10 mass%.  Since this value is larger than the 2 mass% requested by you, and provided sodium oleate is a surfactant anyway, just go ahead.  A gentle warming, like 30 to 40 Celsius, may accelerate the process, though.