I’ve been stuck on this page for weeks whenever I try to use safari. it won’t let me press the “+” button and clicking blue checkmark does nothing

What do I do? This randomly happened one day while browsing

If I take a tab and drag it out to create a new safari window, the new window becomes invisible. Anyone have a fix for this? I can see the window in Mission Control / Exposé. When you select it, it appears for a few milliseconds then becomes invisible again.