hi dear, your baby is still a baby, and curious. and now,he knows he can request and insist his ways because to him, 'No' is not an answer or solution.
it doesn't mean that he is misbehaving, or not listening to you, but more like testing his boundaries. it is ok to instill what he can/cannot do, be firm.
he will be picking up words really soon, and will be talking. keep talking to him and avoid baby talk, teach him to verbalise words, yes, no, daddy, mummy, I want, this ,that, please, sorry. even when he don't say it, he understands
so, I can out advise you to chill, let him be a baby, soon he will outgrow this phase, and onwards to another phase, commonly known as terrible two, but I call it the terrific two.
every stage brings on new challenges.