Scotland is decent for living costs (you wont get stripped dry of money on rent like in the south), but be careful with those jobs. Have a safety net of some sort (like savings or something) because cities with a lot of universities especially generally have tons of applications per job position so it might be a while. Gone are the times where you can for example walk into a bar and get a job straight off, now it's a bit of an ordeal with the waiting and the experience. The only (almost) sure fire way to get a job is to have a friend who introduces you into one... which is why it's useful to make friends at uni early on I guess.
500 quid per month is gonna be sticky, but maybe it's doable. Expect half of that at least to be eaten by rent, and another 50-60 by gas/electricity (though most likely more). Rest for food + expenses, you're going to have to watch your finances closely.
