@Matt Venn could you tell how to integrate a layout done using Magic to caravel framework? Also is it possible to import skywater device models to ltspice?

Caravel or Caravan? For caravan you need to have the top level spice file + user_wrapper.gds needs to be populated with your layout. Same is true for caravel, but for caravel you can also use OpenLane to build the spice file/GDS. You need to use the OpenLane relevant steps in caravel in a process called hardening macros/chip integration

Is there any documentation about the use caraven?

I don't know much about analog submission still

Caravan's github repo has some information. Some are in the precheck repository Caravan top 11 pins are bare pads and it it is tailored for analog designs. Caravel is designed for digital/mixed projects and has no bare pads.

the analog wrapper read me also has good information https://github.com/efabless/caravel_user_project_analog/blob/main/docs/source/index.rst