If you were a parent who wanted the very BEST for his/her children (as ALL parents should)....you can teach and love and discipline and guide and direct. You can be supportive, encouraging, consistent and sincere.........Until a certain age, there is no need for you to discuss what you did or didn't do as a child, in terms of the "things" you mention in your question.
When kids reach a particular age, they may even ask you about your childhood OR you may feel it is appropriate to make a comparison here and there, between your life and what you hope for them.
We parents ALL...also want more for our children than what we had. That's Universal and constant. No need to be graphic and/or painfully open, but it's a really bad idea to ever LIE to your kids. Lies have a way of being exposed, which is extremely devastating to a child at any age.....to know that their parents lied to them.
"Letting kids party," is too general......but I guess I know what you mean by this......
Get it out of their system? That's not a concept I believe in nor do I place any validity in it. They have to have a social life, within reason, at the right time with the right friends. If you raised them well and taught them the differences between right and wrong and they UNDERSTAND consequences....you should be able to let them go, a bit at a time. And always be vigilante and NOSY. You need to earn their respect and they need to earn your trust. If you step on them too often, too hard....THIS is when they want to rebel and GET IT OUT OF THEIR SYSTEM.
"Lazy with schoolwork and no motivation," is NOT acceptable nor up for negotiations. Sounds like you are being very smart and proactive and are intent upon being a good parent. When you finally are one, I'm sure you'll be a wonderful one.