Well first I'd say it may be a 'well paying' job, but most certainly not sustainable by any means. This must be your first job and contratulations on it!
The reason why it usually goes the first week is because:
A. You don't watch your spending, this is something that will take time to learn and assess. When you purchase things, always know how much you have.
B. Separate the 'wants' from the 'needs'. For example: "I want an Xbox One", or "I need to get some soap", there's an obvious difference between the two. One is something usually for fun and not exactly necessary, the other is far more important to get. Make sure to think this as you go purchasing things.
C. Although $100 a week does sound nice, in this day and age, it really doesn't buy much as you will soon see, so that $100 will evaporate quickly if you make hefty purchases like video games (which cost $60...) hence why I don't play anymore...
So the best thing you can do is open a bank account (more of a need than a want), and create a savings account. Each time you get a paycheck, put $50 in that savings account and use the remaining $50-$100 to live off of using the three pieces of advice I gave you. Before you know it, you'll save $1,000 or more.
I'd put half of it in a bank account and save it. Just get it into your head that it's not all to spend straight away, some is to save for the future. Instead of thinking that you get $100, think like you get $50 because the other $50 is for later
Not spending it.
Put it up, out of sight, and out of mind.
If you don't like banks or aren't old enough then get something to put it in that you can't get it back out of without breaking it. Like a piggy bank or glass jar that your hand don't fit into. And as soon as you get a pay check put how ever much you want to save into the container immediately before you have time to spend it. And keep the jar in a place where you aren't seeing it to stare at full of money every day. After a bit you'll learn self control and money budgeting. To not run out and buy every shiny thing you see. Which 90% of adults need to learn as well.
If this job is going to send you a W2 at the end of the year, do yourself a GIANT favor and have your parents help you open a Roth IRA. You can invest in stocks there for your retirement. I know that seems a million years away but, starting now will give a great start.
If you're really slick, talk your parents into matching whatever you put into the account. I.E. you deposit $50, they deposit $50, too.
You should be cashing out a certain amount of money for "walking around" money. This is the money you are allowed to blow on fast food, clothes etc. You are probably living at home so you should probably be able to do fine on about half your income. The rest should be saved for big stuff. When you are out of walking around money for the week, stop walking around.
Umm, don't spend it all? Maybe deposit some of it into a savings account instead?
get a better paying job. Or put aside 50$ of that every pay cheque to save.
