GX20 is currently the only Meraki Go router.
https://www.meraki-go.com/meet-meraki-go/security-gateway/
Read the technical specifications. But yes, it has DHCP, and it's recommended for 50 or less clients. It's also limited to 250mbps WAN to LAN performance.
Though it's only recommended for 50 or fewer clients, it certainly can be used for making more addresses than 50.
If you plan for more clients than 50, you should consider using a different router. Ubiquiti Dream Machine Peo maybe. Meraki Go switches and access points supports VLAN, so can be used with other routing equipment.
About the access points (https://www.meraki-go.com/meet-meraki-go/wi-fi/), it does not say much about max clients per AP. I'd think about 15-20 clients per AP.