In 1958, before I got my Novice license, I bought a second-hand Hallicrafters SX-99 receiver which covered AM BC up through around 34 MHz. It looked great just sitting on my desk, but without an antenna I couldn't hear anything but local (Las Vegas NV) AM stations.
So I took some 22 gauge solid insulated wire, which was what I had available. (The insulation was white with a green tracer, which might have helped...
). I ran it diagonally across the ceiling of my bedroom, supported by a thumbtack on the far end, the ceiling light fixture in the middle and a thumbtack in the corner nearest my desk. From there it dropped just about straight down to the desk and the antenna terminals of the SX-99. It was about 15 feet long, overall.
What a difference! In half an hour, I'd logged a dozen stations on SW, including Radio Moscow, HCJB (Quito, Ecuador), Radio Australia, Deutsche Welle, BBC, Radio Japan ... and I still have their QSL cards and letters!
Your antenna doesn't necessarily HAVE to be any different, although with all the man-made electrical noise that's so prevalent, you might not be as lucky as I was.
Two final points: this was in 1958, during the biggest, most spectacular solar cycle in radio history if not in recorded, pre-SWL history. This was a great time to be involved in any sort of shortwave listening or hamming. CB hadn't come along yet. AND, we generally shun a house covered with stucco because of the shielding effect the chicken wire holding the stucco presents. My parents' house was stuccoed. And that 15-foot wire STILL worked!
Experiment. See what works.
