Barry, we have both metal and non-metal trekking poles in this household. My wife likes telescoping store bought poles. I personally still use modified ski poles for a variety of reasons. First, they can't collapse under load. They can be even lighter than 'trekking poles' because of the lack of hardware. They don't 'buzz'. They can be replaced for almost nothing....I have several by the back door here. I've flown them all over the world, too.
So, you might duck into a local pawn shop and look at some carbon or thin aluminum ski poles, buy a couple, and learn some technique. They work fine on city concrete. Lightning doesn't care about your poles.
You'll learn whether you are a one or two poll-er. I'm a one pole hiker, unless there is a lot of climbing.

Urban hiking is a blast. I'm care taker of a nature preserve in this town and sometimes hike to another preserve five miles away, passing through mine. Also, when visiting another city, long hikes to points of interest are a priority. Boston comes to mind. A fanny pack is all that's needed. Go get some miles!