My keyboard is not the same as when I bought this phone the keyb

I am having problems with my keyboard the keyboard is not the same as when I purchased this phone it is yellow and black and acting up I do not understand it and there's different ads that keep popping up could you please put the keyboard that actually came with the phone back on or do I have to reset the whole phone I do not want to lose the things that I have in my phone though could you please possibly help me with this I would kindly thank you so much help me I really need help with this thank you

/ Chrome 59.0.3071.125</config>