This sounds like it might be a quota issue. I assume that you have billing enabled; if you do not then you should sort that out first :-)
You can see your quotas by zone by going to the console and in the sidebar select "IAM & admin" > "Quotas" then in the drop down menus select Service "Compute Engine API" and Metric "CPUs."
I for example have a max of 24 cores in some zones, and 72 cores in other zones.
Note: if you have a quota of 72 cores elsewhere, and don't really care what zone you use, this would be the time to migrate to a zone with higher quota.
Assuming that the issue is that your quota is 24 in a zone you need 32 cores in, do the following:
- Select the zone with the checkbox on the left
- Click "Edit Quotas" at the top
- Fill out the form on the right
Ideally, if you need 32 cores, approval should be quick. If you have a brand new project, or lots of cores in other zones, it might go to a human. In either case, please put in a reasonable justification.