I have a 2011 maxima with 40k miles I tried to start it but it didn't start I thought it was the battery but all the lights are working perfectly no check engine on what could be the problem

Lets clarify the symptom more. you know the battery is good, but do you know it is connected well with clean, tight connections you cannot turn by hand? When you press start once, what happens ? do you hear anything? and upon repeating the pressing of start, numerous times are you hearing it do anything? Is there a sound of any kind being made anywhere? How many times average does it take to produce a start? Does the engine ever start cranking before the last try where it starts? We cannot see or hear it, so this might help decide where to check first. you have a battery that is filled? with distilled water? The connections are cleaned with a wire brush, then installed and tightened? you cannot turn them with your hand right? What is the condition of the area there and the cables, look clean and new, no corrosion rust or breakage, right? please answer each point. and we can attract some experience perhaps. I can diag a start circuit but I dont have your schematic. you can look for one online, sometimes Autozone website, or ask google for start circuit wire diagram, make, model, year, engine. See where you are after a while.