Make 1 bitcoin in one month without investment it is impossible, there is no way earn 1 bitcoin without investment, if you want to trade then you need capital, if you want to mining then you need tool mining, all need capital or investment
Thats it, even if you want to gamble you need capital to work it. And also you can not make 1 bitcoin earning in a month if you do not do more methods of earning and you will need to gamble to test your luck and hit your target income for 1 or 2 months.