I'm familiar with a fairly high-quality yoga site in terms of content and approaches - openyoga.ru
There are many training materials. And there are quite a few videos of "open yoga" on YouTube.
If you read the basic principles and understand them, you can do it yourself.
Explaining everything here in detail - it takes a lot of time .
Primary and Vital: Remember safety. Absolute contraindications to yoga: alcohol or drug intoxication, mental illness, severe violation of the body scheme. Relative: exacerbation of chronic diseases, excessive physical activity, taking a large number of medications, a course of deep massage or acupuncture, overheating / hypothermia of the body, etc. If you are convinced that everything is in order, then: to understand yoga, do not start by reading literature, but practice, understand yoga with your body! If it is not possible to work with an instructor, start with YouTube, a good coach knows how to convey his knowledge through words, believe me. Here is a wonderful relaxing complex, your body will be grateful (hatha yoga, correct approach to the spine)
And another great channel for beginners, basic exercises and how to do them
Don't overdo it, listen to your body sensations, study yourself!
To start doing yoga, no special preparation is required. If you are only interested in physical exercises (asanas), then I advise you to look at the selections on this channel https://www.youtube.com/channel/UC7wsOPRntlcsBgK-fz7lEiw (Unagrande Yogaclub), if you want to learn about the philosophy of yoga, then you should look here https://www.youtube.com/channel/UCNOjndUve_-AzsvmbPhPbpA (lesson meditation.rf)
Is it possible to stop the development of varicose veins at home? Ready for any action, just not to go to the doctor once again.