Hi @Saowo. Welcome to Bisq
As you may know, cryptocurrencies are transferred and “stored” on the blockchain, not in the individual devices. Bisq handles sending and receiving BTC to and from your trading peer automatically, so you needn’t worry about that. However, if a particular trade involves sending bank transfers or cryptocurrency other than BTC (altcoins) to the trading partner, you would need to initiate a bank or altcoin transfer to the credentials specified in Bisq. You cannot bypass the normal buy/sell BTC process because you never see your trading peer’s addresses. As mentioned before, Bisq handles transfers to and from automatically.
If we talk about altcoins, you can change your altcoin addresses as frequently as you please by creating altcoin Bisq account. An altcoin address is everything you or your trading peer would need to initiate an altcoin transfers. With bank account and anything that falls into the realm of traditional finance, changing your credentials would be difficult because each time you change them, you lose your reputation in terms of account signing and subsequently, the trade limits.
Any trade on Bisq requires both parties to put up a security deposit in BTC, there’s no way around it.
Overall, if you’re very new to BTC, Bisq might not be for you because it has not been built with simplicity in mind, if I’m being completely honest. I strongly recommend getting BTC or other crypto elsewhere first, just to learn how it works. Then, once you have a better understanding of decentralised currencies and finance, try having another crack at Bisq.