Learn by doing
Try a task with a small practice file
Choose a concrete problem, compare the expected result, then use the same workflow with your own files.
Fix a semicolon CSV for Excel without uploading it
Turn a small European-style CSV export into an Excel-friendly copy. Use the practice file first, then repeat the same checks with your own data.
Extract pages from a PDF without uploading it
Create separate PDFs for pages 1–3, page 4, and pages 5–8. The practice document contains only numbered demonstration pages.
Find a trailing comma in JSON and format the corrected data
Use a short invalid object to practice reading a JSON parse error. Then correct the syntax, sort the keys, and save valid JSON.