Including trail period and paid version in the software

I am have few questions about the software launch ( I am not sure if this is the correct place to ask but Thank you anyway).

I have built my software using Java, and Converted it to .exe setup using Excelsior.

1. I want to include trail period/paid version in my software, which includes validating registration codes, etc( Which I am not know). Is there any framework or API or something?

2. I have searched online for selling software and found websites which offer to sell it ( like 3dcart.com , avangate.com ) which say they only host my software and sell it (with some % of cut) or should I buy my own hosting account (in arvixe.com ) and try to sell my software. Can you please suggest me which I should use like avangate or try to host with my own effort.

Thank You!