Thank You, I Ran debootstrap, Now What?

[Linux for blind general discussion]

Well, I installed debootstrap, the man-page listed this command which I ran as
sudo debootstrap stretch ./stretch-chroot http://deb.debian.org/debian
All seemed to go well, I now have a stretch-chroot directory containing  the 
following
bin
boot
dev
etc
home
lib
lib64
media
mnt
opt
proc
root
run
sbin
srv
sys
tmp
usr
var
In looking in duckduckgo, I cannot find how to actually switch to Debian from my 
current Ubuntu? Supposedly that's what this program is designed for. If I could 
switch, would it just be a single tty or would it need to reboot? Running 
Speakup with a DecTalk External U S B. Thanks so much in advance
Chime