Need to have volunteers, and know that you have enough
If doing a multi-lingual event, try to have people who speak multiple languages
Have tables/chairs
Have laptops, for changing/paying for differences
If registration is over multiple days, or has breaks (for opening ceremonies, for example), do you have security/volunteers to stay and ensure that no one comes and takes anything or breaks anything?
A printer (or 2), and printer paper for printing the registration sheets, and any other information required
Waivers or other documents which need to be signed by each registrant
Sufficient pens for everyone (if you’re letting registrants use pens to sign waivers, plan on many of these pens to “disappear” by accident).
Ideally, the registration will take place in an place where people can stay, unicycle, socialize. (e.g. A mall is not great, as it discourages staying/socializing)
If doing registration in a public venue (e.g. Mall, or other public area), there should be promotion and outreach to the public who walk by. Ideally have someone there specifically to explain what’s going on to those who pass by.