When you get it, you should be given instructions from your GP etc. Take it on the first day of your period and then for three weeks, having a 7 day break (in which you get your period). Try to take them at a time convenient to you. My friend started taking hers at 9pm and forgets it so often because she forgets to take it out with her etc. Another friend takes hers at 6pm but also has to be careful with timing as its easy to forget. I personally find it easier to take mine in the morning (I set my alarm for 8.45am anyway, so take it around 9am) as I find it easier to remember as part of the same morning routine everyday (ie get up, bath, teeth, pill) which means I've not forgotten it or had to rush home!!
Some symptoms are normal for the first time, if they're really bad moodswings/pain etc, then just see how it goes and if after 2-3 months it's no different, change pills when you go back to get your next lot.