You check in as few bags as possible as you have to pay for them.
If you fly with one bag in check in each way you should have booked '1 hold bag per flight'
If you fly only one way with and the other way without bag you have a difficult time to book that with EasyJet.
And you only need to change to two bags if you need to check in two bags at the same flight, be careful as they do charge a lot for checked luggage.
I have an interview with Easyjet, what should i expect for the english and maths test?
Firstly congratulations on getting an interview with one of the world's great companies.
Read all the notes that they have given you about the test.
Maths test: I'd guess addition, subtraction, multiplication, division and percentages of integers, money and decimals. Addition and subtraction of fractions. Possibly conversion of metric to imperial given the equivalents and of pounds to euro and dollars given the exchange rates.
English test: possibly dictation, spelling, punctuation, comprehension of a simple story.
You might find something useful for practice at http://www.move-on.org.uk
Why is it that there are no airlines like EasyJet here in the states?
The operation and regualtions between Europe and USA are quite different. Easyjet normally appear cheap, but realistically, last minute you will always find a national carrier cheaper. Low-cost airlines operate by selling the first few seats cheap, and then as more seat sell, and less are left, the prices rises exponentially. Anyway, you get less in low-cost, support your national carrier who'll look after you!
The fee for changing a flight date is £30.00p or €36.00 if done by visiting their website. You will also be required to pay any difference between what you paid for the flight compared to the cost of the new flight chosen.
To make the change go to "manage bookings"
The aircraft will be an Airbus A319.
The scheduled time for the flight is 2hrs 20mins.
Update - Today, Friday, 14th May, EZY 6039 did the journey in 2hrs 02mins.