I've tried making potato puree & potato+carrot puree. Both turns out to be very sticky and i think its quite difficult to eat it. Is it suppose to be that sticky?

potato puree usually turns sticky because it's starch. there are also different types of potato to use for different purposes (mash, bake, curry etc). For mash you will need to use russets which is the small golden colour one. Don't buy the dirty brown potato because it's not meant for mash :)