I have decided to use one of my old PC's (an HP w/Intel I-3) for a VERY SIMPLE project but I am such a novice I don't know how to set up what I want.
I want to be able to hit the "ON" switch on this computer and have it boot to MX (or some other - better for a specific use - flavor of Linux). Once booted I want it to automatically launch Firefox to a specific url (my preferred interactive weather-radar map) in full-screen. It will sit all day long, running on my old "theater" monitor across the room so I can glance at it and see if any ugly weather is approaching my area. If the monitor shuts off after x minutes I can wake it up with the mouse, but I'd prefer that the screen not shut off for at least an hour.
This is all I want. I will have no need for a DE, I will have no need for any applications, I will have no need for ANYTHING except a dumbed-down interactive weather-radar display.
AND - most important - I really am a novice so any instructions/suggestions will have to be very specific.
This is how it looks now - but it's a full-blown version of MXL and requires normal hands-on navigation every time I turn it on. I just want this to appear every time I flip the switch (with no hands-on ANYTHING).

THANKS IN ADVANCE !!