Start here: https://typewriterdatabase.com/imperial.76.typewriter-serial-number-database Try to identify your particular model from the links at the bottom of the page to see specific examples. You can look through individual galleries to find a serial number and that may allow you to find the range of serial numbers made in particular years to narrow down your year. Looks like it's a "standard" from the late 30s or 1940s, possibly an Imperial 50.
Next find a manual (or something close): https://site.xavier.edu/polt/typewriters/tw-manuals.html
Learn how they were used: https://boffosocko.com/2025/06/06/typewriter-use-and-maintenance-for-beginning-to-intermediate-typists/
Consider whether it will be cheaper/easier to have someone service it for you or to do it yourself: https://boffosocko.com/2025/06/23/typewriter-repair-costs-and-valuation-professional-shops-versus-collectors-versus-first-time-buyers/
Go crazy: https://boffosocko.com/research/typewriter-collection/
Good luck!
reply to u/Pleasant-Ad9620 at https://reddit.com/r/typewriters/comments/1mgg7xv/helping_dating_this_imperial_typewriter/