Summer would be a great time to visit Europe. The weather is pleasant and days are longer, which makes it an ideal time to go sightseeing and engage in various activities. It should be noted that June to August is the peak time for Europe travel, hence touristy spots will be more crowded. That should not deter you from planning a trip then though as there are enough secluded places to enjoy some alone time as well. Attaching some Europe tour packages for your perusal. Hope this helped!
Summer is the best season to visit Europe and UK. However, if you are getting married around Feb, and want to go to Europe - Greece, Santorini, Switzerland, Turkey are some of the good options to consider.