When applying for a Master’s degree in England you do not have to go through UCAS like undergraduates do. You apply directly to the universities of your choice. Most of them do not have a processing fee so you can apply to multiple universities.
Application forms: You may complete an online application form or download the form and send it by post. Each application form varies depending on the university but the information requested is similar (e.g. personal details, educational background, work experience, learning difficulties etc.). The entry requirements vary as well. Generally speaking you will need a degree from a recognised university with a 2:1 (send an email to the university asking what grade this corresponds to in your country).
Transcript and degree: Your transcript and degree should be translated and certified in English. This might be pending when you apply so you may give an indication of what you expect to receive as a final grade based on the transcripts of previous semesters.
English language qualification: If your English language qualification is IELTS you need to check if the university requires a minimum band in each section (e.g. minimum 6 in Writing). You may apply for a position at a university before receiving your IELTS results. You will receive a conditional offer and you will be told what grade you require for acceptance. Some universities offer pre-sessional language courses if you are not able to get the band that they require.
References: You are asked to provide references from 2 professors that have taught you. These may be obtained in several ways depending on the university e.g. by supplying contact details of the professors, may be sent by the professor via post directly to a university of your choice or given to the student who scans and uploads them on their on-line application form.
Personal statement: Some universities have word limits for these and include them as part of the application form. Alternatively you may be asked to provide a personal statement separately. This should be one page if possible. You should say something about your current studies, work experience, skills, awards, future plans, why you believe the university is suitable for you academically etc. You do not need to begin with information from your high school as you have moved beyond that.