What advice do you have for a traditional guardsman preparing to retire in the next 24 months?

The absolute most important things are:

Make sure you have copies of all your records from Day one on. Make sure all your medical issues that occurred on IDT, AT, and any active duty are documented. About 9 months before your retirement date, get with a VSO and start your VA claim.

As for your actual retirement stuff, ensure you sign and date every thing correctly so there is no delays in processing. Ensure your point total is correct as well.

Each state runs a couple seminars every year for non-regular (mday) retirement.
Attend one of those as soon as possible, even if it's just on Teams.

You'll want to understand the complete benefits of gray-area (between separation and collecting) and actual retirement.
Your Jordan deployment should qualify for early collection prior to age 60 (6 months for every 6 months deployed after JAN 2008).
And you'll want to get the paperwork right to have that retired pay start on time.

Save everything! Those ‘old’ orders, may be helpful when you file for Social Security!!