As a beginner there are only two knots I know how to do: a bowline, and a 'trucker hitch' This last one I only know how to do one handed, as was taught to me by a trucker in Texas
You lay the rope
in your palm, the load end coming out between your thumb and index finger, then you 'roll' your palm so that the rope wraps on the back of your palm, continue rolling until the load end comes out by your index finger. Then with middle and ring fingers bring a loop of the free end below the line wrapped on your hand (in between your palm and rope) grab the loop with your thumb, middle and ring finger and slid your hand out and tighten by pulling on the loop.
Then, taking care not to pull on the free end, pass the the free end around what you want to tighten, pass it around the loop and then pull down. The loop will hold.
To undo, take the free end out of the loop, and yank on the free end, the knot collapses and dissapears.
Frankly I would have to sit down and study how to doit two handed..by now its so natural I dont even think about it when I am tying something.
It you start with the thumb pointing towards the free end (the wrong way) then when you put a load on the loop it will collapse grabbing the line instead of leaving a loop, so make sure your are properly positioned.