I dont keep any crocodilians myself, and was onyl browsing this out of curiousity, but i do think theres something REALLY important to be thought about here.
alot of reptiles like 1/3 to 1/4 of a humans life. even some of the ones yoou listed as starter reptiles, like iguanas (my primary exp.) live 20 years. Any large long-lived reptile is NOT good for someone still living with their parents. infact, i dont reccomend anyone considering anything that gets over a foot STV until they live in their own home.
its pretty simple... big animals involve bigger space. lizards (i dont think crocodilians count as lizards, but for this generalization, i think they fit into it) tend to need space a MINIMUM of twice their length wide, at least one deep, and depending on in they live in water, ground, or trees, up too 4 times their height. normally, for anything over a foot, this involves what is currently your bedroom as an 8th grader. I made the mistake of getting iguanas while i lived with my parents. I no longer have any of them, and it is directly related to the fact i was not in a stable living place. until you are someplace where you can alter the house to make a forever enviroment for your pet, keepings that do not fit in tanks is just not wise!
and what about when you go to college? its really limiting to have something so hard to care for, you cant take it with you, and its hard to give it proper care. Normally thats when big reptiles get dumped on someone who wanted it bc "OMG THATS SOOOO COOL" and feeds it a highly improper diet, bad enclosure, improper lighting and heating, etc etc, or it gets pawned on mom and dad who had no intention of caring for such a pet.
this isnt fair to you, your pet, or the any number of people from shelters to parents who may get stuck with it at any point. If you're so dedicated to wanting one of these animals, find a place that has them, a shelter, a rescue, someone down the street who happens to have one, and take advantage of a learning experience!
Honestly, do your parents even know what they are getting into agreeing to it? The space in their house it will take up, the fact that in about a year or two (im guessing) they will probably need to make some sort of a pond for this creature? The fact it could easily turn into a dog sized aggresive unhandleable creature?
it may seem obvious, but i know despite how obvious it was when i showed MY parents the giant green lziard i was about to buy, THEY didnt understand the fact they were about to sacrifice a room to him.
and you know its really likely that at some point, being so younge, you will ahve to move on and you will be forced to give up your reptile. This isnt just bad for the reptile, being forced to loose the sweet scaley you loved so much is like loosing a family member, and odds are you wont ever see him again.
-----
1.3 Dogs (max, tasha, kaya, screw)
1.0 Ghost Corn
1.0 Ball python
0.0.1 Red tailed Boa
0.0.2 Red Eared Sliders
0.0.1 Softshell
0.0.4 insane tarantellas
2.1 ferrets (Otis, Milo, Monty)
1.0 Cat (Kitten)
0.0.1 Emperor Scorpion
0.0.1 Melleri Cham (Sir Arthur Chamleon Doyle)
And an ever-changing fishie tank...