Customization Questions

Hi there, I really like the look of this theme on our webpage so far, but would like to make a few small changes. Specifically, 1. How do you make the text on the navigation menu bigger? 2. When viewed on tablet or smartphone, the menu says "Secondary Menu." Is there any way to change this text to "Menu," "Main Menu," or delete it completely? Best Regards, John www.kyotojalt.org