Hello, everyone. This is my first post, I'm a complete beginner who wants to get somewhat good at using Inkscape.
I am semi-familiar with path tools from GIMP and I want to create objects with the bezier tool, but it doesn't work the way it does in Gimp. What confuses me is that whenever I join the final node with the node I started with, it doesn't give me the shape I drew. What it results in instead is completely incomprehensible to me.

I'll give you an example:

This here path is in the shape of a square


You click to connect the nodes and finish the path, and then...

...where did this line come from??

Hope you can help me!

Welcome aboard!

Check the tool's settings
-set regular Bézier path, and shape:none.
Probably you have triangle:in instead which is supposed to work with open paths.

(Those setting which Lazur refers to are on the control bar, which is just above the horizontal ruler.)