Don't buy a lot of shit (furniture, boats, cars, etc) - as Swanee pointed out, stay "light and nimble."
Also, try really hard to believe in yourself - it'll help you have a little more fun. I spent the first year or so of flight school waking up each day wondering what it would be that finally caught up and got me the boot. As it turns out, if you make it through the various filters and put in the work, you'll probably be alright. I had three neighbors, each with significant amounts of previous flight time (I had none) and fancy technical degrees from A-list colleges. I was the only one to get winged (as a pilot). Two attrited altogether; one got winged as an NFO.