Check out from below centres.
Brahma kumaris
Art of Living
Isha Foundation
Vipassana

Dzogchen practices aims for Moksha Yogic practices will help individual for preparations.

Not sure about youTube channel. well its best you experience meditation from genuine sources. some are given below.

1. Brahma kumaris
2. Art of Living - sahaj samadhi meditation
3. Isha Foundation
4. Vipassana

All meditations will make you feel safe and secure to some extent. you can try visualization meditation with an intentions. I suggest you do regular asana and pranayama.

I think you are talking about desk job and you are getting neck and shoulder pain due to that. You need some shoulder mobility and stretches.
you can try our 30 mins class(30 min : Yoga for Eyes, Neck and Shoulders)

You do any style of Yoga it will help you in obtaining the right posture. you can start with Hatha yoga to begin with.