What, do I have to follow the dress code exactly like this?

Okay so I’ve been homeschooled for a while and I am planning to finally start at a public high school by next year. The high school I’ll be going to, I went to their website to see if they showed the dress code online. The dress code is very important to me. At the school they said something like shoulders should be covered and no holes above the knee on like jeans, I’m okay with that. It’s just the skirts and the shorts part. I’m the kind of person who likes wearing skirts and shorts with leggings and different patterned tights such as fishnets underneath. The skirts and shorts I wear I make sure are as long as my hand when I put my hand straight down by my side when I stand up. I looked at what it said online and it said that shorts must be 5 inches I think from the top of kneecap as measured by a ruler or the width of a 3 x 5 index card and that skirts must be 3 inches from the top of the kneecap as measured by a ruler or the length of a 3 x 5 index card. Now I am pretty much scared a little and I keep thinking that I won’t be able to express myself how I like in high school. I understand if you’re showing way too much skin and looking like a slut in school, that’s explainable. But my friend who goes to a different school than me but is around the same county area said that she got in trouble wearing just black leggings with a skirt. I know every school is different but I’m afraid that since our schools are in the same county area, the dress code could be the same. I don’t know, I’m just afraid I won’t be able to wear tights or leggings with a skirt if I wanted to because that’s how I love to dress. I was just wondering, do you always have to follow the dress code exactly? Will they notice if your skirt is like a little shorter than it’s supposed to be? Thanks for taking your time to read all of this!