[Don't know how to describe]merge two lines? close the circle? sorry, i have pictures

SOLVED NOW, idk how to change i
Okay so i’m completely now to this, and I’ve been following some tutorials but i got lost pretty quickly and since i’m pretty much new to 3D modeling, i can’t even describe my problem or look it up on google, only thing i can do is post pictures and hope people will get what i mean.
so how do i put these together or close the circle(i’m creating an eye), when i try they get incredibly close, but they are still not together… sorry for my English.
Here’s another pic without the squares.

And here’s a picture of my whole screen, if that matters.

Thanks for reading and i hope you get what i mean and can help me solve this.
Also if you need the video I’ve been following ill tell you that too.

Merge (Alt-M)

There are many ways to do this. The simplest I can think of to delete the end vertex, mark the other two and press “F” (Make edge/face).
Keywords to use on google can be: vertex, merge, snap


You can also press “W” and select merge, it might be more comfortable.

Thank you all so much for replying, i solved my problem with F since it looked the easiest.