I was actually able to jailbreak my IPhone successfully. However, it seems like a lot of the repos that existed before like hack your IPhone or insane i don't exist. I also tried to install IFile, but it gave me this error during the installation process:
Complete
Done : iFile
Running Debian Packager
Selecting previously unselected package
Repo.biteyourapple.net.iFile
Reading database ... 3276 files and directories currently installed)
Preparing to unpack
.../repo.biteyourapple.net/iFile_2.8c_iphoneos-arm.iFile ...
Checking device compatibility iFile
Unpacking repo.biteyourapple.net.iFile (2.8c)
Preparing iFile (iphoneos-arm)
Unpacking iFile (iphoneos-arm)
Preparing to configure iFile (iphoneos-arm)
Running Debian Packager
close_round_fillSetting up repo.biteyourapple.net.iFile.2.8c
Failed in buffer_write(fd) (8, ret=-1)
Sub-process /usr/liexec/cydia/cydo returned an error code (1)
I tried to use Cydia Impacter to side load the app onto the phone, but I can't figure that program out. A guide told me that it'll detect your IPhone when it opens while it's plugged in, but it didn't.

you can install filza
and hackyouriphone still  available and its updated
not sure about biteyourapple though
insanaly is gone

Restarting did nothing. It took a little longer for the error message to show up, but it still showed up.

I wonder if, by chance, the jail break for iOS 12 does not function correctly at this time. Either that, or it doesn’t work with 12.0 and you have to update to 12.1.  Either way:
The indicated repository could not be found. This could be because you are trying to add a legacy Installer repository (these are not supported). Also, this interface is only capable of working with exact repository URLs.

I used to Z jail break.  Not exactly sure how good it is, at least to other people, but for me it doesn’t work very well.

There is currently no jailbreak for iOS 12

Hi.
Sideloading just means getting an app on your phone without going through the official app store. Cydia Impactor is one way to sideload apps onto an iOS device. All you have to do is open it up, select the file to sideload, enter your Apple credentials, and off you go. There are four types of jailbreaks for iOS devices.

Tethered jailbreaks are the least desirable because they require you to have access to the jailbreak tool on a computer every time you want to reboot your device. If you're out and about with no access to a computer and your device reboots or shuts down, you're simply out of luck.

Semi-tethered jailbreaks are similar to tethered jailbreaks, but your device will still be able to boot to the non-jailbroken state. However, you still have to use a computer to re-jailbreak.

Semi-untethered jailbreaks boot to the non-jailbroken state just like semi-tethered jailbreaks. However, they don't require a computer to re-jailbreak. A sideloaded app is usually used for this purpose instead. Most jailbreaks that have come out in the last couple years have been semi-untethered.

Untethered jailbreaks are the most desirable because once you're jailbroken, you are set. Every time you boot your device, it automatically boots into the jailbroken state without you having to do anything. Jailbreaks like Absinthe and Evasi0n are untethered, but iOS 9.1 is the latest version with an untethered jailbreak available.

no untethered jailbreaks
all of it is  semi untether

Give it up; jailbreaking is dead!
No, seriously!  Cydia creator Jay Freeman says it's not worth it, Luca Todesco who is probably the best known iOS hacker today has quit jailbreaking things for you like, last year, and Apple is making it harder with greater security fixes and increased proffit for hackers who find vulnerabilities, meaning that you're pretty much on your own now if you actually, ya know, really wana try your hand at jailbreaking, which could end up costing you your device and anything on your device owing to vulnerabilities.  Once upon a time Cydia was the appstore; today your 10 year old nephew is being taught by Apple how to develop for them.  Third party apps are more readily beeing swallowed up by the giant because phone sales aren't going as swellingly as they would have liked, so they have to pick up slack through revenue on the appstore itself.
In short, that means that jailbreaking will realistically only give you a small modification in comparison to what you would have gotten like, 5 years ago.  If you're not satisfied with iOS and you feel there are just too many restrictions you probably should switch to an Android device of some kind... I honestly can't blame anyone for wanting to have their cake and eat it too... I'm just too old now to care.

you can still jailbreak if you are on IOS 12 to 12.1.2. just search unc0ver.