What are the basics of Greenhouse gardening and how can I start it?

I haven't seen any Tutorials or threads about Vertical Gardening here? Please explain me how to start it and how can I achieve the goal?

I was wondering whether I should buy a plastic greenhouse that is made from plastic acessories or should I go with Metal Greenhouse?

What can I grow in a small greenhouse ?

Does plastic is used for any frost protection in Greenhouses? if so how?

I have seen online so many are growing mint using stems with large area. Do I need red soil or any other compost for growing mint?

poison in aloe vera?

I was looking to hang pots in my balcony so far the place is very small that making to utilize as much as I can. I have seen many gardeners who hang on walls, roofs and balconies. I just want to know what can be grown leaving flowers?

What are the methods for making DIY hanging basket colums ? please post with images so anyone can understand it.

Could somebody tell me the best possible method to Gongurra plant at my home? I love to eat it a lot, but to Covid disease it's hard to buy from market.