How can I secure a canvas carport to a concrete pad?

I highly doubt that a canvas carport is going to withstand 30mph wind. Does the manufacturer claim that it does,or are you just hoping?

If the manufacturer has provided base plates with screw holes, then these should be sufficient for the design loading (whatever design loading the manufacturer chose). You can try making the carport-to-ground connection stronger by other means, but the carport will just fail in a different way (e.g. canvas ripping or rods bending).

So, if you are happy that the canvas carport itself is good enough for your purposes, then you can just put screws through the foot pads. Make sure the screws are nice and long and are properly anchored in rawlplugs. Or maybe drill and resin-fix anchors in the right place in your concrete, with the anchor bolts going through the screw holes. (Actually, with regards to this, surely you have some sort of installation instructions with the carport, which should tell you how to anchor it to the ground? Unless what you've actually bought is a gazebo intended for garden use and to secured down with tent pegs.)

To secure the base of the steel support you can use a concrete screw. TapCon is a ubiquitous brand TapCon screw that has worked well for me. You will need to drill into the concrete with the correct size bit (5/32" or 3/16") to accommodate the screw length.

Another fastener type (Redhead is one brand) Redhead bolt is one in which after drilling a proper sized hole the fastener is inserted and then sharply struck with a hammer. The force of the hammer drives a metal shield around the bolt to expand outward which wedges the threaded post rigidly in the concrete. The machine screw threads can be used to fasten the base with SAE nuts. Lastly, you can drill an opening in the concrete and insert a lead shield. This is basically a HD wall anchor. After tapping into the concrete a bolt is tightened into the shield it will expand to tighten against the wall of the hole.

Using a hammer-type drill with a masonry bit will facilitate the job of drilling into the concrete. I found when using expansion-type bolts that vacuuming the dust from the hole enables the expansion shield to hold and stay wedged as it is being tightened.

A canvass carport wont last 2 minutes,invest in something stronger, use metal 3x3” floor shoes to support 3x3” wooden uprights and build your own carport with a tin roof, will look better and last somuch longer plus protect your car better too :)