Questions[download-manager](ubuntu)

In order to install Xtreme Download manager, I've used the following commands based on what is said here.

sudo add-apt-repository ppa:noobslab/apps
sudo apt-get update
sudo apt-get install xdman  

But here's what I get from the terminal and I can't get it installed:

sepideh@sepideh-Lenovo-ideapad-700-15ISK:~$ sudo add-apt-repository ppa:noobslab/apps
[sudo] password for sepideh: 
 This PPA Contains Applications for Ubuntu/Linux Mint from different sources but debianized by http://www.NoobsLab.com
 More info: https://launchpad.net/~noobslab/+archive/ubuntu/apps
Press [ENTER] to continue or Ctrl-c to cancel adding it.

Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease
Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [83.2 kB]
Ign:3 http://ppa.launchpad.net/noobslab/apps/ubuntu bionic InRelease
Hit:4 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Hit:5 http://dl.google.com/linux/chrome/deb stable Release
Get:7 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
Err:8 http://ppa.launchpad.net/noobslab/apps/ubuntu bionic Release
  404  Not Found [IP: 91.189.95.83 80]
Get:9 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]
Hit:10 https://repo.windscribe.com/ubuntu zesty InRelease
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/noobslab/apps/ubuntu bionic Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
sepideh@sepideh-Lenovo-ideapad-700-15ISK:~$ sudo apt-get update
Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:2 http://dl.google.com/linux/chrome/deb stable Release
Get:4 http://security.ubuntu.com/ubuntu bionic-security InRelease [83.2 kB]
Hit:5 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Ign:6 http://ppa.launchpad.net/noobslab/apps/ubuntu bionic InRelease
Get:7 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
Err:8 http://ppa.launchpad.net/noobslab/apps/ubuntu bionic Release
  404  Not Found [IP: 91.189.95.83 80]
Get:9 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]
Hit:10 https://repo.windscribe.com/ubuntu zesty InRelease
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/noobslab/apps/ubuntu bionic Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
sepideh@sepideh-Lenovo-ideapad-700-15ISK:~$ sudo apt-get install xdman
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package xdman
sepideh@sepideh-Lenovo-ideapad-700-15ISK:~$ 

What should I do?

I installed this stupid downloader flareGet as I am not satisfied with it so I would like to uninstall it up?

And, can anybody suggest me a downloader as quick as easy as IDM on Windows?

Is there a download manager that can open multiple connections to the specified URL and download part files only to join the files later and present it as one single file?

I know about wget, but as far as i know, it opens a single connection to download. (Though can resume a interrupted download)

Is there such a download manager or a command line tool available?

I am really new to ubuntu and using 14.04 version. I have heard that Aria2 is one of the best download managers. How can I change the directory using terminal so that it can put the file on a specific hard drive after it finishes downloading?

Earlier I was using Windows 7. It was having IDM (Internet download Manager) from which I was able to download almost all the types of files from the internet. I was also able to download online streaming videos by the help of IDM. It was really helpful for me regarding the downloading. I was also able to resume my downloads which were paused or stopped due to some reason.

So, I would like to ask that whether there is any software in Ubuntu form which I could get these functions and if there is any software, then how to download it.

I am a new user in Ubuntu. I am using Kubuntu 13.04.