I run with a guide and have done a few runDisney races!
If I remember correctly, you sign up as a visually impaired athlete when you register (this is standard for larger races). (Otherwise just email them after registering).
You can get a guide from runDisney, which is not standard for races but super awesome! I ran with a guide from runDisney my last race even though I ran with my sister which meant she and I didn’t have to run together.
RunDisney has a AWD (athletes with disabilities) tent in the pre/post race area. If you’re registered as an AWD you might have to check in there? It’s where you would meet your guide if you use a runDisney guide. You can leave things like a white cane there.
Just to be aware, running a race guided is totally different than running a race not guided or going for a run with a guide. RunDisney in particular is crowded and has a lot of first time runners who might not realize you’re guiding. I think rundisney will give you a bib for his back that says visually impaired runner or athlete with a disability, but I can’t remember if they give you one for yourself that says guide.
The best way to get through crowds for a race like this is to avoid crowds, which I think just means starting in an earlier corral? I wouldn’t do a lot of stopping for pictures until you get the rhythm of running guided in a crowded race.
All that said, I think rundisney races are some of the best to run with a guide because the make the process pretty smooth! Have fun!