what sure for level design

This one is my main project and i am trying to come up with a concept of another easier game and im going to work on the easy one and work on the main one every now and then but do you have any idea what i should use for level design

ok thx, and what about destructible environments?

What should i used to make Levels or maps? and how would i make them destructible

Im kind of in it by my self so im going to have alot of work to do and i knew it would take a while so i guess ill work on it for a year then enter it in next years contest that will give me time to work on it and improve on it

I wondering how would i make a 2D Stealth action side scroller shooter with 3D Models and  i am not sure what programs should i used for the animations, Models, and level designs? I have (not very good) drawings of the characters, drawings of a few levels and, Some of the Weapons. I would appreciate if anyone could help me out with some ...

I wondering how would i make a 2D Stealth action side scroller shooter with 3D Models( if its possible) and what programs should i use, i am not sure what programs should i used for the animations, Models, and level designs? I have drawings of the characters (not very good), drawings of a few levels and, Some of the Weapons. I would appreciate if ...