What is the process to check the Click-Through Rate (CTR) of my PPC campaign

Simply go to your campaign manager, and then you can check the CTR for each campaign, but my suggestion would be to check the CTR on the keyword level to understand the performance even better, now with the CTR in front of you, check either you got sales with high or low CTR? if you get sales with low CTR that could mean your product is being ranked either lower 1st page or top 2nd (3rd) page if you get sales with high CTR that could mean you get sales from top of search or mid 1st page, from this assess whether the click is way more than sales or not, around 1 click out of 10 must convert to a sales, so target that and optimize accordingly, though this is quite a high number and can vary from product to product.

The CTR is displayed as a percentage and represents the number of clicks your ads received divided by the number of times your ads were shown. You can analyze the CTR to measure the effectiveness of your PPC campaign. A higher CTR generally indicates that your ads are relevant and engaging to users, while a lower CTR may indicate the need for adjustments to your targeting, ad copy, or bid strategy or placements.