battery charger needed

[biker bob]

so i bought a rad city 5 used online and it needs some love ,  it did not come with a charger iam told battery works tho . also both brake levers are broken and the gear changer was missing right hand side . 
then i had a friend say i wont be able to use it because there is no key ?
is this true i was not told nor given a key and i do not see where one would go . .
please can someone point me in a direction on what i should do about this .  is my bike now useless or am i able to get the parts needed maybe used or could i buy replacement from the company its made by .  please say i did not waste 500 on something i cannot use as an electric bike ....