You'll do great! I did my first century last fall (after only having been riding for about three months). It was going to be the Seagull Century, but the weather prediction was so horrid that I didn't want that to be my first experience, so I switched to one on the Eastern Shore of Virginia the month after the Seagull.

I did fine with just bars and whatever they provided at the various stops. I did make sure to eat every time food was offered, regardless of whether or not I was hungry, because I was sure I'd need the fuel.

I don't think you should do a long ride this weekend. You'll be fine having done only 60 miles. ("Only"! Did you ever think you'd consider 60 miles to be "only"?)

The best advice I can offer you is to not linger too long at any of the rest stops (including lunch). You don't want to stiffen up.

And, like others have said, break it down mentally into smaller chunks, especially near the end. I found that helpful once I passed the 60-mile mark and still had 40 miles to go and was out by myself in the middle of no where, without another soul in sight. I'd just tell myself "Only 17 miles to the rest stop. You can do that. You do that all the time."

Let us know how you do!