First time claiming expenses for uber. What to add in Unclaimed capital cost?

If were not self-employed last year, then you wouldn't have an Unclaimed capital cost. You would enter your assets as additions for this year, then next year you will have a Unclaimed capital cost for them.

Im filling for 2023 tax and i was doing uber during that time. I was calculating CAA. So what should i put in UCC? 

Like I said, if 2023 is your first year in business, you will not have a UCC.