There are different types of mediation. Guided meditation is led by a teacher, coach or guide and this can be in-person or using by audio or video. Guided meditations vary in length. Choose a length of time that is comfortable for you. By searching Guided Meditations on the internet you will find numerous choices that can be downloaded at no charge.
YouTube has a wide choice of Guided Meditations.
Guided Sleep Meditation – The Healing Spring 31 minutes
https://www.youtube.com/watch?v=28rLLb1g5sg
Inner Peace 32:42 minutes
https://youtu.be/e33dETmxAr0
Let Go of Anxiety, Fear & Worry 22:21 minutes
https://youtu.be/4EaMJOo1jks
Guided Sleep Meditation for Clearing Negativity 58:43 minutes
https://youtu.be/VttsLIfV2pM
No Anxiety Meditation 10:15 minutes
https://youtu.be/f6ssmZIV-go