Can i make an update /upgrade with sudo apt-get?

Hello dear developer! Can i make an update /upgrade with sudo apt-get command from ssh ?Or just update in the classic way via etcher ?

Hello.
You need to edit apt config.

Nano /etc/apt/sources.list
And replace wheezy to something newer, like stretch

This will allow you to install some stuff, however, this is not how it should work, may be unstable.