You need to come to Tooting, it is spice heaven, and also super cheap quauilty veg, better the supermarket.
I understand that it can be intimidating, however bare in mind that Indians have a completely different body language. British Indians mostly don't, but in US they are less heavily populated. When I went to India it was completely different.
They are business minded, so they don't want discourage white people from shopping.
They can be brash, but actually mostly of them are really nice. They tend to have a formal polite way of talking. These shops are really cool. Does your self veg? Often they have better produce than supermarkets, and it is not over packaged.
Even if you don't ask, it the produce is no going to kill you. Try bitter gourd.
https://en.wikipedia.org/wiki/Momordica_charantiaIt is bitter, but healthy and I like it.
Regarding spice tea, or other dishes:
I suggest you don't try all the spices at once. Try single spices like cardamon, cinnamon, clove, ginger, fennel, black pepper in small quantities. Btw even something as simple as pepper, you can get better quality in these places.
Cardamon is deceptively strong, especially if fresh (fresh cardamon is bright green rather than the pale green that is commonly sold). Use the smallest whole one you can find. Or you can break one open and use 2-3 of the seeds. Black cardamom has a completely different taste, more savoury and subtle (but great for long cook curries an stews). You should leave this to brew for some time in hot water to infuse it.
Nutmeg just a tiny amount. Star anise is too, as is a little anise. One small clove.
Caraway is underrated IMO. Cumin, is very strong and has a generic madras taste if over used.
Some of them you may want to dry roast to get the aromatics. This is heating them low flame without burning for around 30-60 seconds. cloves puff up, fennel also works well.
Then you can work on combination 2-3 at a time. It changes things dramatically.
I am actually used to a lot of spices in food. I'd like to get some green cardamom, star anise, cloves, etc. I know that the quality of spices is much better than what I'd find in a supermarket. I like curry pastes, too. I'd like to get some higher-quality premade ones to try before I'd make my own. I actually eat cinnamon sticks by themselves on occasion (true cinnamon, not cassia). I also chew on fennel seeds sometimes.
I enjoy "hot spicy" foods as well. I tend to enjoy foods with a lot of flavor, such as south Asian, southeast Asian, east Asian, Mediterranean, Mexican, etc.
I find many European foods to be lacking in vegetables and often bland. I'm not putting these foods down, but I don't enjoy the tastes as much. And I'm not much of a meat eater.