Merge process not clear

I have 15 years of detailed data in 14 accounts, all on my desktop. In mid-January , I was forced to relocate from my primary residence to a second home, and installed Quicken/WIN on my laptop. I downloaded a backup of my primary file and restored it on the laptop. Other than memorized transactions, there are no data duplications for the period Jan 6, 25 through today, May 8, 25. I need to utilize Quicken Web from now on. I believe the laptop has all the data prior to Jan 6, but there appeared to maybe be some things that weren't exactly right. If I sync my desktop, I would need to add just the 2025 data. If I sync the laptop with Quicken Web, I might still have some issues. What is the best approach to get everything on the Web, for subsequent use on either computer, which are located 3 hours apart. One other note, which may not be significant, is my desktop uses the Classic view and the laptop uses the new screens.