Unless you were personally there, saw it, and have video or photographic evidence, leave the trashing of the other side to your child custody attorney!
Spend your time talking about how the kids do well with you, and all the things you do RIGHT. Anticipate the bad things they might say about you and soften them by acknowledging any weak spots (Yeah, I let the kids stay up late and watch the Super Bowl, so we were tardy the next day for school, but that was the one and only time) or whatever.
If you are going to be seen as reliable, you need to be knowledgeable and if you can’t even keep any of your dates straight, you will seem more likely to be making it up.
If you aren’t good with dates, that’s ok. Keep a journal so you won’t forget them, AND you can reference it to prepare for your court date months or years later.
Marijuana, vulgar words, and offensive themes (such as wearing a confederate flag shirt/hat or a shirt that says F-the-popo) to your hearing are great if you want to get off to a BAD start with the judge before you even get started.
Small or big, lies make EVERYTHING you say look bad at best, and completely false at worst. If you are lying about 1 thing the judge and other attorneys will call EVERY SINGLE THING into question.