First, fix your "supposed to be automatic on and off" cooling fan(s)!!
Second, flush your cooling system if you haven't done it in a while to clean it out.
Third, add a 50/50 mixture of straight antifreeze and clean drinking water or 100 percent a new type 50/50 mix that is now being sold..
Forth, install a new thermostat and before doing so, carefully drill two, 1/8" holes in it to help "burp" all the air out of your system.. Then fill your system completely up with coolant as above...
I know, you may not have to do all or even any of this but why not start with a good system to begin with!!
And I even change all the hoses AND fan belts periodically too to make sure onna them suckers doesn't decide to pop and leave me stranded which has happened before!!!