You can have a common SSID for your wifi and the attached devices will select the strongest channel as you roam around the home. Most of the time and bearing in mind this will not work as well as it does with a commercial wifi installation.
IME, it does work better than having separate SSIDs for each access point in which case the devices will stay attached to a far access point in preference to a closer one with a different SSID. They should be on different channels from among the three non-overlapping channels of 1,6, & 11. Select the channel numbers to avoid conflicts with neighbors if possible.
Other SSIDs can be used for various other purposes.
Guest user, so the password can be changed without messing up local users connections.
Temporary non-encrypted connections, when holding a party, for instance.
Assuring the printer or other device attaches to a specific access point.
Broadcasting a punk message for your neighbors to see.
I give my printers (and some computers) a static IP by setting my DHCP to assign IPs within a range starting at .100. All IPs lower than .100 can be static. Most drivers do not need static IPs to find the printer, but it makes it easier if you want to use the printers HTML management page.
But probably a better way is to dig into the router's DHCP settings and reserve a specific IP for the printer by its
MAC address.