Changes for bitcoin.conf file and details on the testnet network bitcoin-core

I have installed bitcoin core testnet and it is now synchronized with the network after 24 hours.

My question is about bitcoin.conf file.

I will tell you the procedure I used to install:

I created the start testnet.bat file with this command : start "" bitcoin-qt.exe -regnet -datadir=./data_regnet/ -prune=550

Now There is this bitcoin.conf file in "data_testnet" folder. But the thing is it is empty.

And as I am new to this so want to know should I make any changes to bitcoin.conf file or leave it as it is.

And another question is right now I haven't closed the wallet in fear of losing the synchronization that it took so long, So the next time when I want to access the wallet I can directly start my start testnet.bat file??

Operating System: Windows 10 (x64-bit)
Bitcoin-core version: 0.16.3

Thank you:)

bitcoin.conf is a file where you can define configurations to bitcoind and bitcoin-qt persistently, you if you don't want anything like that, just leave it empty. Here you can find more about the possibilities.

And another question is right now I haven't closed the wallet in fear of losing the synchronization that it took so long, So the next time when I want to access the wallet I can directly start my start testnet.bat file??

That's ok to restart it. Assuming you start bitcoind or bitcoin-qt with the same data directory, it will continue with the progress from the last session.