I love this question @ngergov. I’ll dive in with some ideas, and I’d love to see some more folks who have “changed instances” present their best successes too.

As starters:

• Understand your C360 / R360. It’s among the most-visited pages in an instance, so your fluency on a 360 will likely inform you well on the instance.
• Appreciate where you data is arriving from, and where it’s going to. Same as above...the more you learn about how your data arrives and is processed, the firmer your understanding will be.
• Review the Rules Engine, to understand what runs regularly and why.

And a non-technical approach:

• Spend significant time with your people. Set conversations with the biggest users and stakeholders. They are a gold mine of information about what’s working well, what’s not, and what they envision a tech stack doing for them.

I would also add the following as secondary things:

• Get to know the data in key objects: company, company person, person and the same for relationships if you have relationships
  • Completion rate
  • Quality
• Check the discrepancies between C360/R360 and the key objects to get a feel for the state of “dismay” the org is or isn’t in
  • When I took over my org, there were… dozens of fields that contained no data (and couldn’t because not in C360 so who’s going to consume or populate…, weren’t in reports either), broken mappings, undocumented fields… that showed me (even though I was new to the app itself) that basic maintenance didn’t happen.
• Repeat with playbooks, CTAs, timeline entry types etc.

It personally helped me “weed” the instance (and do a deep spring clean), and consequently continue to build on sounder foundations (albeit not perfect).