If you have started playing guitar and haven't yet purchased an amplifier, then you are missing out.
When you do get amplification, it makes everything much more fun.
Practice guitar amps come in all shapes and sizes and have a variety of features that may not make sense to the beginner.
Consider these and the alternative to amplifiers.
Get a commercial brand practice amps.
Most of these amplifiers are small and in the sub $100 range.
You are getting most likely an 8" to 10" speaker.
It should have fairly basic mixer, headphone jack, and possibly distortion although many won't have this.
These are nice when practicing alone but quite honestly rarely can keep up over the sound of drums.
Use your computer speakers.
It's likely you already have decent computer speakers.
A couple speakers and sub woofer can be bought in the sub $30 range when you find a deal.
Most computers have a 1/4" input jack either a line in or a microphone jack.
A $1 adapter will make it so your guitar cord will plug into this.
In all honestly, this is going to sound just as good as a practice amp.
You have the benefit of mixing the sound on the computer with all sorts of computer software that can change the sound.
You can also record yourself.
Buy some high quality headphones.
You may consider buy high quality headphones instead.
If you are using your computer, these can plug into that.
When you do upgrade to a better amplifier, these are still useful when you need to keep the noise down.
If it's just for practice, it's really just for you to hear.
Buy used and save for the upgrade.
If you need to buy something, but an amplifier that's used.
As you get better you are going to want to upgrade anyway.
And when you do, you are going to want to get something nice that can be used for gigs that can be heard with or without a sound system.
Get your amp and keep practicing.
Make sure you have enough material and exercises to stick with it and get better at playing your guitar.