Set up ring network for the first time ...

Hi everyone!

Struggling with how to set up the desired topology outlined. I have a Fortigate 60F that is liveand will use it to connect 5 new switches. The question is quite simply how the switches should be set up against each other? How do I proceed? Never set up any network stuff before...

How should I set up the connection between the Fortigate and the two switches? One link must be given priority. Also want the focus to be speed between the various switches. Aggregation? Set up one switch against port A and another on port B on the Fortigate? Which ports should I use?

The idea is also to have two links between each switch.Thanks in advance! Appreciate any help I can get.