New 18.04.2 installation problems

I'm new to Ubuntu - just installed a week ago and not familiar with terminology. My desktop has no top menu. I can't see the 3x3 dots Application icon shown in U-Tube guidance videos. When selecting Software in the menu I get SSL handshake error. I can't load any software e.g.can't link my HP printer. Guidance appreciated.

Right away it is apparent that you did something wrong because the current point release for Ubuntu 18.04 is 18.04.6, not 18.04.2.

18.04.2 came out in February 2019, almost three years ago. This is not appropriate for having installed Ubuntu a week ago.

You should download and create bootable installation media based on an up-to-date release and then reinstall Ubuntu.

Don't forget to verify the integrity of your download and flashed media to ensure that the download and the flash are uncorrupted. If your installation media is corrupted, it greatly decreases the chance for a successful installation.