Understand your credit score without the scare stories

Help me understand credit scores in plain English.

What I'm applying for: [phone contract, mortgage, rental, credit card, or just curious]
What I already know: [score range if I've seen one, missed payments, CCJs]
Recent applications: [any]
What worries me: [optional]

Ask me up to 3 short questions first if anything important is missing. Wait for my answers.

Then:
1. What a credit score is and isn't, in five lines.
2. Factors that usually help or hurt, in plain words.
3. Myths to ignore (including paid 'boost' promises).
4. A short action list relevant to my situation.
5. Point me to MoneyHelper for official-style guidance, and say when to check my statutory credit report.

Do not invent my score. Only use what I've told you, leave blanks for anything I haven't given, and don't invent facts, figures or products. This is help organising my own numbers and wording, not financial advice; point me to MoneyHelper, GOV.UK or Citizens Advice for guidance, and to a free regulated debt adviser if I'm struggling to pay. UK English.

Stay in this ChatGPT chat. Do not turn on apps or connectors, and do not use memory from another chat.