How to Practice Vocal Warmups

Hello. I've just begun the 30 day singer course by Jonathan Estabrooks. In the course, he shows us warmups like lip trills and advanced lip trill slide. But I don't understand how I should practice these warmups on my own. I do not own a piano and also do not know what scale to practice in. I'd like some guidance on that. Thanks.

Hello! You are meant to sing along with the instructor and follow the pitches they're singing or playing on the piano. If it's still not clear, please check out my course - I have mp3 downloads for different voice types on each exercise.