LucyE I've only had an iphone a short time but have not had much to do with this aspect of it,lol. Learn as I go
I understand, but honestly, if you're not very familiar with it, getting some help is worthwhile.
I have tech savvy family members so just ask them, but I was pleasantly surprised how good the Genius Bar staff were when I was in for another issue. I watched them help other people and have since recommended others to go in.
Things like setting up your security, ability to locate a lost phone, restricting in app purchases, password frequency etc. understanding these things and customizing your phone allows you to use it to the fullest.
Most 'free' apps make their money in other ways. It's rare for a free game app to not have either linked advertising or in app purchases.