Guerrilla usability testing involves finding test subjects in public spaces and asking them to participate in the research. So a first vital step for conducting a successful test is to find the right participants that that represent your target audience.
When running the guerrilla test, make sure you have a strong internet connection and provide participants extra context around the test and your product. Limit the scope of your test and keep your list of tasks short and simple—ideally, sessions should last no more than 15 minutes. When the test is over, offer participants a small gift as a thank you for their time.