Which site I can use for testnet
🙏
There is no need to create a separate topic as long as the topics are related. You can ask everything you want about Test net in one place, but what are you trying to learn? I saw that you are asking about several topics related to electrum. You can find what you are looking for here ---->
https://electrum.readthedocs.io/en/latest/for testnet coins you can use faucets or PM @n0nce