I live in the northeast and the weather is very hot. Can anyone advise me how to grow thai basil.. Thai holy basil and coriander. What soil is best for drainage? Do they have to be in the shade or in full sun ?? What about watering and fertilizer? I am a complete beginner.So I do not even know what pot to buy.... Any help would be appreciated..

I'm sorry to see that this question was overlooked all these months. But this forum is not the best for horticulture. Go to the Farming In Thailand Forum for better access to experienced growers with generous information, not just on commercial farming, but all matters for all growers, with an organic grower subforum. It's under-utilized and a fraction of usefulness that it used to be with ThaiVisa, half dead but still alive.

This Plants, Pets, Vets forum may be better named Dogs, Cats and Snakes (with an occassional plants discussion) 😉.

I think best for the request is to grow in containers, with a good homemade soil mix, -native soil/peatmoss/sand- plus a COF (complete organic fertilizer) with mineral and biological amendments.

Container plantings can be moved to accommodate changes in the seasons. Now through April-May is the intensly hot dry season, then the hot and rainy season. Go with partial/afternoon shade, and good water management. Intense noonday - afternoon sun and water deficit are killers. The monsoon season downpours will get soil too wet, leach nutrients, and allow root-rot. So best to be able to move the plants or provide cover as needed.