Are there services which I can offer to earn bitcoins? Yes, I am a noob at this. I was wondering if anyone could let me know if I could do something sitting on the desk to earn some crypto-pie.
Also please explain how will I be able to use my bitcoins to buy other commodities - like recharge my phone and stuff.
The best I can suggest you is to offer some services to third parties and get paid in cryptocurrencies. 

If you have any skill which can be "sold" on the internet you should use this to try and earn some crypto money. This can range from coding to video editing, freelancing, writing, etc.