Create a new currency, ok but after

For several days, I try the bitcoin system to understand how it works. I do not have any precise stops but I manage to do something interesting. For example, creating a new string of blocks (like that of bitcoin is really really big!)
So I download the source of a currency crypto to try.
Yesterday I managed to generate my first block () on my currency (I was pleasantly surprised) but now what is the next step if I want to continue to develop this currency?

enter image description here

I supose that I should you start up the piece software (ui) to make transactions? How to know the value of money? Etc.

Recent Questions – Bitcoin Stack Exchange

What is the difference between transactioninput.getFromAddress() and transactioninput.getConnectedOutput().getAddressFromP2SH(networkparameter))?

I was expecting that, in the case when getFromAddress() return a address, the transactioninput.getConnectedOutput().getAddressFromP2SH(networkparameter)) should return the same address, but sometimes is the transactioninput.getConnectedOutput() give back null value despite getFromAddress() return a proper address. What is the reason?

If these two methods are inherently different, how could I return the value of field “addr” of the object “prev_out” of the items in the array “input” in the JSON object returned in ex. this blockchain api call with bitcoinj and without the use of

Recent Questions – Bitcoin Stack Exchange