A CV should make real experience easier to understand. Adding impressive responsibilities that you never held creates a different problem: you may be asked to explain work you did not do.
A practical way to start
Provide factual notes about a role, project or volunteer activity. Describe the tools used, the work performed and any result you can support. Leave unknown dates or figures visibly unresolved.
Prompt to try
Turn these factual notes into three CV bullet points. Use clear verbs and concise language. Do not add employers, qualifications, team sizes, percentages or achievements that are not in the notes. After the bullets, list details I could supply to make them more specific. Notes: [facts].
Check the result
Read each bullet and ask whether you could explain it with an example in an interview. Replace vague claims such as “excellent leadership” with a real activity where possible.
Keep the final wording consistent with your actual skill level. “Assisted with” may be more accurate than “managed”, and accuracy is worth more than a stronger verb that changes your role.