As others have mentioned it looks like like you are using the default Window Manager. You can install others that will provide a more familiar taskbar for you

As others have mentioned it looks like like you are using the default Window Manager. You can install others that will provide a more familiar taskbar for you (that is a taskbar on the left of your screenshot). I've like LXDE and XFCE in the past, Im currently using KDE + Plasma, its only been a couple weeks so Im still learning it but might switch to another. Long story short you can definitely find a taskbar that will meet your needs for Ubuntu.