Almost everything is correct. One thing deserves attention: The two pronouns for what in English is just "you": "jij" (also shortened to "je") en "u"

Please: Alsjeblieft, Alstublieft
Thank you: Dank je wel, dank u wel. Dank je, dank u.

Note that there are spaces in "dank je wel", but not in "alsjeblieft". That's just how it is.

So as you can see, these expressions have two varieties, one more polite than the other. "u" is for people you don't know well or for people you want to show particular respect to (elderly, a teacher at school), "je" is for friends and relatives, or for when you're sure you can talk "as if you were friends". "u" therefore obviously is safer, and people will tell you that you may say "jij" to them if they'd rather have that. A lot of people (even if they might appreciate being spoken to with "u" at first) are not comfortable with people saying "u" to them all the time because it indicates distance.

"Prettig met u kennis te maken" is good, but I tend to say "Aangenaam kennis te maken", which is more common and means exactly the same.