There are many displays for Raspberry Pi and following some of the manufacturers instructions isn't always so easy.
But there are scripts available which will make it very simple.
As an example, in this post, I will install the LCD touch display from Joy-IT RB-TFT3.2-V2. The size is 3,2" with a resolution of 320 x 240, has a touch display and comes with 3 buttons.
Upgrading from Jessie to Stretch can break the entire system so ALLWAYS do a backup.
There are several sites/posts with "how to" information but the Raspberry site, the Linuxconfig site and the Superuser site, (where You can find more details about the upgrade), made the base for this post.
Updated 2018-02-14 !
This backup method will make a copy/image of the whole card even if there is very little data on it. So if the card is 16Gb, the backup file also will be 16Gb. On the other hand You can ZIP the image file to save space.
Another, maybe smarter ?, backup method is described here.
