ConwayLife.com

The direct way to change the rule is:

Open the "Control" menu and choose "Set rule..."
Either: in the input box enter "B3/S23", OR, from the "Named Rules" drop box choose Life.
You may also want to set the algorithm to "Quicklife"
Click "OK"

Alternatively, you can open a Life pattern from the Patterns directory and the current rule will change back to Life.

Natejasper wrote:How can I set Golly back to just use the basic Conway GOL rules - after loading a few things

Adding to what wildmyron said -- you may also want to set a keyboard shortcut for this, which can be done in Golly's preferences. Golly doesn't assign keyboard shortcuts to most things by default, but I've found it's handy to have Alt-R assigned to "Set Rule" so I don't have to click through menus every time.

Also, welcome to the forums! For future reference, it's best to ask questions such as these in an existing thread, such as the thread for basic questions, or the Golly 3.1 thread. People who're already subscribed to these threads are more likely to see your questions there.