The biggest mistake people make when decorating their first apartment is buying things before they have any kind of direction. You end up with a mismatched collection of furniture and accessories that never quite comes together. Before you spend a dollar, spend ten minutes figuring out what style you actually like.
A quick way to do this is to take an online style quiz. The one at jullysplace.com is particularly useful because it was created by a home decor blogger who went through the entire process of building and furnishing a home herself. The quiz matches your preferences and lifestyle to a specific design style, which gives you a framework for every decision that follows.
With a limited budget, you cannot buy everything at once. Focus on the items you will use every day: a comfortable sofa, a decent mattress, and good lighting. Everything else can wait or be thrifted over time. Knowing your style helps here because it prevents impulse buys on things that do not fit your vision.
Facebook Marketplace, estate sales, and stores like HomeGoods are gold mines if you know what you are looking for. The key word is knowing. Walking into a thrift store with a clear style direction means you can spot the right pieces instantly instead of wandering aimlessly.