Good to hear from you. You’ll find a whole bunch of iPad enthusiasts in this Forum who are only too willing to help other iPad owners and to hear of their experiences. Don’t be afraid to post any questions you may have or use the ‘Search’ button near the top of the Forum web page. I usually find I discover one new interesting and useful piece of information about my iPad every day - and often not even what I was looking for!!
On the iPad there is no 'normal' way of closing apps, like you would on a PC - and no real need to either. You have discovered the multi-task bar - which allows you to move from one app to another and this is the normal way of switching apps. When you do this, the iPad should remember the context (state) of the app that you are leaving ready for next time.
So, if you leave the YouTube app by double-clicking the Home key and then selecting Safari it should return to Safari exactly where you left off previously. However, you say that when you return you are faced with a 'white page'. In fact, it should return you to the Forum page that you left when you selected the YouTube video. There is an issue with Safari that it often has to reload the web page that you left - so that might take a second or two. Is the page you return to white - or a checkerboard pattern?
One 'tip' that most iPad users have found is that, when things start acting a little strange, it's time to turn the iPad on and off again - i.e. a complete turning off by pressing and holding the Power button until the slider control appears. Normally we all just briefly press the Power button, which puts the iPad into sleep mode only.
Switching the iPad on and off - no big deal, after all you often turn your PC off - allows the iPad to 'tidy up' its memory and some other things and often fixes 'unexplained' issues....
If the problem persists, don't hesitate to get back in touch.
Hope to hear from you soon with your thoughts about the iPad.
Have fun and enjoy your iPad
If you don’t already have it you can download a copy of the iPad manual for free.
Apple - Support - Manuals
It’s free too.
Tim
Scotland