Travelling to europe cheapwestern city to fly into and general tips

[recondite7]

I am planning a trip to europe this summer and I am trying to find out the cheapest way to get there and back.

I've done some early research but I want to know if anyone has advice regarding:

Cheapest city to fly into out of

Best time in the summer to go (month, day of week etc.)

Best time to book online airfare in relation to the time the flight leaves (2 months in advance?)

Also any other advice from people who have gone to europe recently regarding places to stay, where to visit, train passes etc. would really helpful.

Thanks