Recovering my password from google/ gmail

i have two google accounts my original one and a new one.i am useing a friends rca viking pro/ android. i am trying to recover or change my password from my original gmail account. iwant to put my original gmail account on her tablet, i already have my second gmail account added to the tablet.i am haveing problems pulling up and adding my other account. tring to find my password or change it, i been fallowing to steps as said but when i try they want to know what my password is. but the reson i am wanting to find it out is to access my account? i hope this all makes sence to you all. i am not to computer smart or really know my way around aot of the term or things they say or ask i am preety much lost.please help me ...thank you.