I am looking for my first smart dimmer
I have a track light with 3 led dimmable bulbs
I am not sure what to use Caseta switches or just a z-wave dimmer
my setup now is small just starting out
It depends on what your long-term goal is. Decide on that first.
If you want rock solid reliability, go Lutron Caseta, but you will need the L-BDGPRO2 hub. I’ve got fifty-something Caseta switches and dimmers, rock solid. One plus is that the Lutron hub also has integrations with Alexa and just about everything, and it sure made it easy for me to migrate from my C-5 to my C-7, 90% of the migration was done by just moving the Lutron hub.
However, I did replace the Caseta switch or dimmer in each of the bathrooms with the GE/Jasco Z-Wave Plus Smart Motion Switch or Dimmer (26931 / 26933). Nice switch and dimmer with unobtrusive integrated motion sensor, and Jason Bottjen (@JasonJoel) has a nice component driver for them that separates the motion sensor device from the switch/dimmer, and that also permits automation control of the various modes of the device. So, if you are considering coupling motion sensor control of your lights, consider that approach.
Check first to make sure your LED lights are dimmable by whatever solution you choose. You can adjust the trim on the Caseta dimmers to avoid flicker on low levels, or you can add a load trim resistor. The GE dimmers accept a pretty wide range of LEDs. Again, check.