First time Lucid Dreaming and questions

Hi guys this night was the first time i had a lucid dream , i always was interested in it so i read a lot of stuff on reddit and knew how to react and do a reality check , so i checked myself in a mirror and checked my hands but they look normal to me , they were only a lil bit vaguely.. so i knew i was in a lucid dream. since this was the first time i wanted to try stuff out ( like walking through walls ) but without any success... so i walk outside to try stuff outside and the first thing i saw is a woman that try to sell me pineapples for some reasson LOL... after that i tried to wake up since i needed to go to the toilet... I dont know how to explain it but everytime i tried it was like something prevents it. eventualy i woke up ... Very cool experience and was suprised i was not panicking , i hope this will happen more but unfortunaly i think i was lucid dreaming since i needed to go to the toilet :/ My question is :

1. how to end a lucid dream properly? what are good methods ?
2. Howcome i cannot changed things in my dream ? like walking through walls / flying ? Is it
   because it was my first time or ? ...
3. I was in lucid state because i needed to pee? My apologize for my english , its not my main language but i think its readable and understandable :)