Hi KrissyLou, here's what I suggest:

(1) Remove any unwanted extensions (2) If necessary, fix your home page setting (3) If necessary, fix your default search engine (4) Run a cleanup scan

For #1, you can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Command+Shift+a (Windows: Ctrl+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then cast a critical eye over the list on the right side. No extensions are included with Firefox; all are optional. If in doubt, disable.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

For #2 and and #3, see:

• How to set the home page
• Change your default search settings in Firefox

For #4, this software is popular (and free): https://www.malwarebytes.org/antimalware/mac/

It’s very sad, but many of the software downloaders / installers will trick you into installing not only their program, but other programs as well. You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print. You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does. From now on, everyone needs to Use The Manual Option to put a stop to this.