You could buy a pickle spice mix (this one is a North Indian style pickle mix, by the looks of it):

https://foodsofnations.com/products/indian-pickle-masala-ach...

Here's a 'wet kind' to make Gujarati style pickles:

https://www.tarladalal.com/homemade-indian-pickle-masala-guj...

Here's a recipe to make mango pickle (this being the tail end of summer, you may chance upon raw mangoes still): https://www.tarladalal.com/spicy-mango-pickle-mango-pickle-w...

Or try pickling lemons, which are easily available year-round:

https://www.tarladalal.com/sweet-lemon-pickle-nimboo-ka-acha...

https://profusioncurry.com/sweet-lemon-pickle-recipe/#recipe

Raw sour mangoes, chopped to eighths, with the seed taken out. (hard shell covering the seed is fine, but there's a thin film that is inedible on it, take care to scrape it to prevent choking hazard later). Mustard powder. Seeds freshly ground is better. Red chilli powder Salt. Methi seeds. (fenugreek seeds. You can find at asian spice stores usually). Gingelly oil.

The most simple and basic aavakaya (andhra pradesh style mango pickle with mustard) is as follows:

1 cup heaped mustard powder, one cup heaped chilli powder, one cup (not heaped) salt. A handful of fenugreek seeds. Mix evenly. Toss the mango pieces in this. Add a little gingelly oil to wet the mixtute and help the mixture stick a bit. Place into clean jar. Glass or ceramic, avoid metal. Add a generous amount of gingelly oil. You don't need to top the vessel or make a layer.

Wait 2 days,then mix the entire jar once with a strong, deep spatula (or a clean hand, but beware the spice and wash very very very well afterwards).

This will taste good from day 2. It's a very distinct taste from a matured pickle, and I always eat a little when it is fresh. It will slowly mature over 6 months to a year to its final preserved taste.

Takealittle of it to a smaller vessel for daily use. Do not leave a metal spoon in or use a metal container.

This can be experimented with as little as 2-3 mangoes. About half a cup of salt chilli and mustard should be enough for this.

Also, this is just the simple recipe. There's a lot that depends on ingredient selection which can not be summarised as easily. Clean ingredients and avoiding introducing additional moisture will ensure it will stay good for atleast a couple of months. Well made pickles last multiple years.