I'm afraid I do not quite understand what you're asking for here

Do you want to create a level yourself for others to play or do you want to play a level others have made????
I presume it's the first one, but with all your questions I'm not really sure any more. Learning to make a level takes months( and even years)....it's not something that people can walk you through from A to Z and it's not something you can do over a weekend. It's something you have to LEARN and learn it by YOURSELF. Most people are willing to help you with specific problems that can arise when using the level editor, but very few(if any at all) have the time or even desire to walk someone through making a level as it(as mentioned before) takes a lot of time and energy and is not something that is done in a day.
I will repeat what I've said before, as I'm not quite sure you've understood what I meant. INSTALL the Tomb Raider Level Editor. If you have Tomb Raider Chronicles it came on a CD with the game. With that program(the level editor) there is a text manual complete with pictures and explanations. STUDY it thoroughly. THAT is how you learn how to make a level.
Forgive me for saying so, but I think it's a bit bold to start talking of how you're going to play your own level if you haven't even started getting a grasp of how the level editor functions. We all have to start at the bottom and for level building the bottom means reading the manual and starting to experiment with building the first room/tutorial level.