The biggest trick is not to see it as some huge catastrophe and feel guilty about wanting to enjoy a pizza and beer. Have it and then back to usual eating.
If you know you are going out in evening either fast until dinner or eat mostly protein and veg for breakfast and lunch then have your pizza and beer in the evening. If fasting makes you over-eat the pizza later then just protein and veg meals during the day may suit you better. Do a really good glycogen-depleting weights session the day of the pizza session. After your pizza session the next day fast as long as you can - until lunch-time or dinner whatever suits or afterwards have a few lower carb days. Its up to you to make it work if you want to include pizza and beer in your lifestyle.