Hello Sitara and welcome! Stir frying takes us to another world, or at least another place in this world. It's a great place. Just a quick thing for you to stir fry chiciken.
Cut chicken into small thin strips. Dip into beaten egg whites and dredge in corn flour (corn starch). These go a few at a time into a hot - Hot! wok or frying pan with high sides. You will have about a tablespoon of oil in the wok and hot! I use peanut oil. Stir constantly and cook for about 3 - 5 minutes until chicken is golden brown and just cooked. Overcooking is easy and ruins the chicken - practice with small batchs. Be sure not to overcrowd the pan as hot and fast cooking is the key - overcrowding cools the oil making the result a soggy mess. Drain on paper towels and taste test. And then modify as needed. Add slight amount of oil as you go as needed. - Easy on the oil!
When you have stir fried up a nice table size batch of chicken you can return to the hot pan, add acouple tablesoons of soy sauce, and or a couple tablespoons sherry and a touch - 1 talespoon of oyster sauce plus some salt and pepper plus cashews if you like - about a third of a cup. Toss over high heat for about a minute and a half.
Hot and fast so be sure everything is premeasured - you have no time to stop and measure anything once you start.
Start with maybe a pound and a half of chicken breasts or thighs. This will make stir fry chicken - I didn't include veggies but once you have practiced just a bit I'll bet you want a simple cook book of stir fry recipes.
Just remember - thin strips, bite size, minimum oil, hot and fast, everything premeasured. Good luck.