Setting up Mikrotik and 4G modem, how to distribute the Internet?

Question

Mikrotik

There is a MikroTik RouterBoard RB951Ui-2HnD router and a ZTE MF827 usb-lte modem.
Please tell me how to set up a router for the Internet, so that the Internet from the 4G modem is blown up by wifi and lan ports.
DHCP client created, NAT created. The router sees the Internet, it pings from it, but there is no Internet through wifi, there is no through lan ports either. The configuration is by default.
The second question is how to create a guest wifi network and redirect all client requests to a specific address.

Answer 1

and now the million dollar question - will you show the configs?) in Mikrotik there is not much "default configuration" at all, except in the bridge from 2 to 5 lan and wi-fi, nating to the first port by masquerading.
therefore, either we call psychics, or show the configs. previously - you are doing something wrong with masquerading.

Answer 2

I forgot to enable NAT