Since I brought it is saying technical problems. I try downloading app' it does not allow it. Something about the device. Even some app tablets has not let me.

Normally Samsung’s already have a “download” folder on the main apps screen. Depending what app you use only certain ones with root access will allow you to change the destination folder.
Rooting your device will allow you to fully customise options like this though. But be warned. Rooting is a whole other story and not something you should attempt if you’ve not done it before.

I rooted android devices years back there use to be some apps that would allow root access without actually rooting the device itself. But it’s been so long now I doubt the apps would still be active today.

setings ,,storage ,. make default storage ..,. sd card n walla ,,

on a tablet all your down loads are in the " my files " which must be accessed in the pull down menu , if you opened it in a browser.
However movietube is in the play store as an app . if you got it from the app store . and it installed but is not showing then you have a full screen an need to tap the all apps icon lower right corner . it is the square with rows of dots. then search till you find it. if not then get it from the app store / play store i checked and it is there.

Have you tried to hard reset the device? To do this just press and hold the power and home button and the same time until you see the screen go black and the apple logo appear , now let go of both buttons, allow the tablet to start up. Try the facebook app again, does the problem persist? If the problem still persists, check to see how much space you have on the tablet, sometimes the limited amount of space on the device can prevent an app from functioning correctly. If you find there is not very much space remove several items, to create more storage space, then attempt to use the Facebook app again, does the problem still persist? If so, check the App Store to see if there is an update for the facebook app, if you find one under updates, install it, try to run the App again. I hope something here has helped you resolve your issue.

tablet cannot download apps

If it is a FIRE then it may have an app like MAIL running in the back ground. Turn off all apps. It's a tablet, it will only last a few hours.
The eReaders last for weeks, the Tablets last for hours.

If it's an eReader then on the home page search for jfhjfhj - if it says 4 books not indexed then you have 4 books corrupted, go DOWN and delete those 4 books from the kindle and redownload them.

it gives me my two phones displaying where it says device. neither of them is it. i caanot input the correct device. it will not allow me to do so

it says error because it isnt compatible wit your device

uninstall the wallpaper app