I'm trying to burn a DVD on an iMac and Nothing is working

Question

I Purchased a new iMac with the intent to edit videos I've shot and burn them to DVDs.  I discovered that the new operating system has no video editing or DVD burning software in it.  I tried several software with no success. Then I got roxio Toast 12 pro. Ok that says its compa

Answer 1

If iDVD was not preinstalled on your Mac you'll have to obtain it by purchasing a copy of the iLife 09 disk from a 3rd party retailier like Amazon.com: ilife 09: Softwareor eBay.com.  Why, because iDVD (and iWeb) was discontinued by Apple over a year ago.
Why iLife 09 instead of 11?
If you have to purchase an iLife disc in order to obtain the iDVD application remember that the iLife 11 disc only provides  themes from iDVD 5-7.  The Software Update no longer installs the earlier themes when starting from the iLIfe 11 disk nor do any of the iDVD 7 updaters available from the Apple Downloads website contain them.
Currently the only sure fire way to get all themes is to start with the iLife 09 disc:
This shows the iDVD contents in the iLife 09 disc via Pacifist:
You then can upgrade from iDVD 7.0.3 to iDVD 7.1.2 via the updaters at the Apple Downloads webpage.
Export the slideshow out of iPhoto as a QT movie file via the Export button in the lower toolbar. Select Size = 480p.
Open iDVD, select a theme and drag the exported QT movie file into the open iDVD window being careful to avoid any drop zones.
Follow this workflow to help assure the best qualty video DVD:
Once you have the project as you want it save it as a disk image via the File ➙ Save as Disk Image  menu option. This will separate the encoding process from the burn process.
To check the encoding mount the disk image, launch DVD Player and play it.  If it plays OK with DVD Player the encoding is good.
Then burn to disk with Disk Utility or Toast at the slowest speed available (2x-4x) to assure the best burn quality.  Always use top quality media:  Verbatim, Maxell or Taiyo Yuden DVD-R are the most recommended in these forums.
You do know that the new iMacs do not have an optical drive needed to burn CDs and DVDs, right.  You'll need to get an external optical drive.  I suggest you avoid Apple's Superdrive as that is only USB 2 capable and is a slot loader.  I prefer optical drives that are either USB 3 or FW800 capable.  You can find such drives at otherworldcomputing.com. I bought and use this one: 24X OWC Mercury Pro 800/400+USB3 SuperMulti-Drive.
It is a drawer loading drive which is less likely to get a disk stuck in it.  It also is very fast when reading disks or ripping music CDs.
Toast can create a video DVD as can other apps available from the App Store.  However, none of them are as versatile or can create multiple menus or looks as professional as iDVD.  The last version of iDVD, 7.1.2, works with Yosemite.