Something is long if it goes for a considerable way in one direction. Something goes for a long time if it happens for an extended period.
The lizard in the picture has a very long tail.
The opposite of long is short.
A lookout is a high place that has a nice view. Lookouts are usually set up so you have somewhere to stand and look or take photos, and they have a guard rail so you don't fall off.
If you are on the lookout it means you are keeping watch for something.
A loop is made by taking something long and thin and bending it over so it encloses a space in the middle. A loop might cross over itself or just curve around.
The bag handles in the photo are all made out of loops. When you tie your shoelaces you make two big loops in the knot.
Your clothes are loose if they are too big for you. The opposite of loose is tight. The woman in the picture is wearing jeans that are far too loose for her because she has lost weight.
If you lose something, you do not know where it is. If you are lost, you do not know where you are. The picture is of a teddy bear someone has lost. Lose is not the same as loose.
The opposite of lose is find or win.
The past tense of lose is lost.