My experience, when it comes to learning hebrew, is that slang matters. Luckily for me, most hebrew slang is English words spelled in hebrew letters. All you need to do to fit in and become your inner Israeli is start using these fun hebrew words I have written for you.
פליז-please
סורי-sorry
זה לא פייר- its not fair
בכיף- with pleasure/with fun
תהניי- have fun/enjoy
(M) תתחדשי/ תתחדש (F)- enjoy your new thing
חחחחחחחחחחחחחח-Hahahaha
נו-come on
קריטי/כריטי- critical
whatever-סתם
באמת-It means really and is usually asked as a question
ממש- (usually used to emphasize) really
יאי- yay
ווהו- whoa
Don’t confuse (יש- there is) with יששששששש-yay
נראלי- it appears to me/I think
me too-כנל
Used as a term of endearment added to names. Example: אלכסנדרהוש, נעמיוש. Pronounced oohsh-וש
גינס-jeans
נישנוש- a snack
-Alexandra