🐧 Reboot and select proper boot device or Insert boot media in selected boot device and press a key

Hi, I wanted to dual boot Ubuntu along side my Windows 7. I've made 200 GB partition for that purpose. I downloaded Ubuntu 18.04.4 and made my USB drive bootable with Rufus. First I'd like to say that I've tried to google it, youtube it, ask friends, facebook groups... You're my last hope!

When I'm installing it, I go "Something else" and I make 3, or rather 4 because he forces me to: - 20GB for root * 16GB for swap area (I got 8GB of RAM) - 256 MB for EFI(it won't let me without it) + ~170GB for /home (The rest)

"install succesfully finished"
I've tried this several times, 13 to be exact, I get 2 types of errors:

1. ALl I get is just a command line that says:
   >error: no such partition,
   >Entering rescue mode...
   >grub rescue>
   

So I've tried to 'ls' and I get several (hd0, msdos?) 'items'. I've 'ls' through them to find on which one of them my system lives. When I found that I go:

grub rescue>set boot=(hd0,msdos?)
grub rescue>set prefix=(hd0,msdos?)
grub rescue>insmod normal
error: no such partition

If there wasn't this error I'd just go ">normal" and it should fix the problem.

Now because of this error I put a Win7 USB and boot it from USB. I got 'repair computer' and enter the cmd.

$diskpart
$list disk
$select disk 0
$list partition
$select partition 1
$active
$exit
$bootrec /fixmbr
$bootrec /fixboot
$bootrec /scanos
$bootrec /rebuidbcd
$exit

I try again and it didn't do anything. This was happening 10 out of 13 times.

1. My last 3 tries went something like this:
   "install succesfully finished"
   

And when I restart it to complete the installation and to boot in Ubuntu only the following text shows up:

"Reboot and Select proper Boot device
or Insert Boot Media in selected Boot device and press a key\_

Now I've found a few options to overcome this problem but it seems I don't have those options somehow.
I have UEFI(The 'fancy' BIOS) and I cannot find "Hard disk drives" in it. I've clicked on every thing I could click on.
I know how to change boot priority since I've 'installed' from a USB, but that doesn't seem to fix the problem, many tutorials show 'IDE configurations' and 'Hard disk drives' and do 'something' there. I cannot find that in my UEFI.

Can anyone help? :)