Congrats on the new ride; it's very nice.
Regarding pedals, I went through the same thing when I bought my first bike that didn't come with them.
I had tapped out my funds on the bike, and didn't want to spend more on pedals and such.
So I got some cheap plastic ones. Reading here, it became apparent that pedal bearing friction is maybe the biggest single energy waste in non-committed cycling. They didn't used to be so bad; they used to have good bearings, but slowly, they got cheaper and cheaper, and the bearings are what suffered. Go to the bike shop and try the bearings in your hand of some cheap pedals vs. some nice ones. You won't believe the difference.
I wasn't sure about clipless either, until I tried toe clips. Those things are for the birds. Just junk hanging everywhere, and if you're not using them, they're upside down and scraping on the pavement.
I finally just charged a set of Shimano pedals to the tune of $125. Believe me: once the financial pain is over, you'll not regret the purchase. The ones I bought have clips on one side, and are flat on the other. Thus, they're slower to use, whether you're wearing clip-in shoes or flats, because you have to find the right side for your footwear. But you never have to worry about being caught without the right shoes or being uncomfortable while riding.
Those Shimano pedals are on my cyclocross bike, but I use them 90% of the time with regular flat shoes. But I have the option of clipless when needed, and the rest of the time, I have low friction bearings.
On the urban bike I just got, I knew I didn't want clipless, but I didn't want high bearing friction either. The stockers were slick plastic pedals with terrible bearings. So I bought a set of aluminum pedals with good bearings and protruding setscrews that act as the grips against my shoe soles. They're great. They were $50.
Spend some money now on the pedals and a good U-lock. If you're going to save money anywhere temporarily, save it on luggage and racks and lighting. Although nicer lights are a pleasure to use, an inexpensive set of LED lights will see you safetly through many rides.