Use the
RadioReference Wiki for potential answers. There is a search area at the top as well as sections below with quite a bit of information.
A "dongle" can be various things, but based on you asking in this forum a dongle is typically a device with a USB plug that receives a range of RF signals. It can plug directly into a computer USB port and one would use software to control it. There are inexpensive dongles such as the
RTL-SDR device (which fits the dongle term) around $25, or an improved SDR device like the
SDRPlay products ranging from $110 to $280. There are additional SDR devices and they can be bigger, better and more costly. Devices like that I would not consider a "dongle", but the more you know the better.
I use the inexpensive $25 dongle above for dedicated receive of one frequency, but it is not limited to that. Still, I prefer to use the SDRPlay devices for monitoring due to their improved features. There are other devices as well. It is easy to start off with lower cost dongles and if that suits your hobby fun, there is room to grow depending on your budget.
That being said,
your antenna is more important than a dongle. A $1000 SDR device will only perform as well as the $5 antenna it is connected to, just with more features.