I have 300k and need to start photography studio. I have camera already. what are the things to buy to make it standard setup? thanks

First off what type of camera and what type of computers? I’d assume the Rebel series since your budget is 300k. Whatever it is you do, know that in business, your craft is just 10%, business is 90%. Get a good business location and network with your clients in the best possibly ways. You haven’t mentioned what other props and gears you have but you might want to get the godox SK300 with softboxes. I’d get a barndoor with gels so I can play with colors but that’s just me. Get a three seater leather sofa, get seamless papers/canvases with the stand. Develop a very good customer relationship. I assume you might already have a computer.