Hello I’m Khelma and I’m in the UK I want to get a visa for my mother as she wants to buy somethings

Buy somethings? I think she'll need a tourist L visa. Filling in the application form online is the first step, and the basic requirements are as following:
Passport
Visa Application Form (filled in online and printed out) and Photo
Documents showing the itinerary including air ticket booking record (round trip) and proof of a hotel reservation
With all of them prepared, you need to submit the them to the nearest CVASC.