It's an impossible question to answer to First did you consider visa issues and fees?
What kind of travelling you want? What are your comfort limits?
What I recommend you is to get an airbnb account if you don.t already have one. a blabla car account for Europe and figure around a job you can do while on the road. Have you ever heard of that organic farms that provide accommodation and food in exchange of work? Couchsurfing is also a must to look into.
HI Sahil, the amount of money required would vary a lot depending upon the country you want to include in your plan, how you are travelling, the kind of accommodation you are staying in. The best way to go about it is you move to the country on your list and then you work there while your stay to earn a living and do not move on unless you have made enough.
It depends on your accommodation and places you want to visit. coz every place have different visa policies and prices. I suggest you to make a chart about the countries you want to visit and research the countries visa prices. for free food and stay find hosts on couchsurf and get free stay and food. hope it helps happy travelling