Most Spring Breakers go to the same spots every year; Cancun, Miami, etc. Take a quick glance at a map and pick any place that sounds warm. You can even make up a city, a few good syllables with "island" slapped on to the end should do the trick. No one can call you out for not going on vacation to San Gato-Cerdo Island if there aren't any landmarks or resorts to reference.
Obviously if you could afford to go some place for spring break, you'd be rubbing the whole trip in your friends' faces on social media, but spend a little time on google images and you can do this right from your parent's basement. Save an awesome sunset or a giant margarita to your phone's library, throw on an "I could get used to this" caption and you're as good as there.
Whether you get stuck somewhere with your family or your parents are worried about you traveling, annoying relatives and vacations go hand in hand. Drop some vague complaints about how your Mom "like wants your spring break to suck" and your fictional plans will become infinitely more real and relatable. Meanwhile you'll be eating all the food in your parents house without a spending a dime.
Talking about the weather on any given day is 80% bullshit anyway, so use this to your advantage. Make generic comments about how it rained one day but was also really humid another day, then real nice the last day. You'll bore anyone into heavy sleep before they can even begin to see through your web of lies.
Nothing says you're out having a crazy time like an intoxicated facebook status proclaiming your love for your new home away from home. Set an alarm to wake up at 3am and get to sloppily typing. Tag some friends who you wish were "liivn the lifee!!1" with you, be sure to mention what you're "sippin on" and top it off with some palm tree emojis. When you eventually see your friends you can make up an epic story or just tell them you partied so hard "all the nights blurred together"
For the last step you can almost be completely honest and still perpetuate your false spring break tale. Explain how you spent nearly all your "savings" on your "trip" and you'll get sympathy for your empty wallet while also adding to your narrative. If all goes according to plan you will successfully make people think you went on spring break and since it "cost sooo much" your friends will have to buy your drinks at the bar for the next month.