When I’m the first one visiting a house and/or when I’m the first bidding on the house, does the selling agent has to start negotiations with me in these instances?

Together with the seller the selling agent decides the way negotiations are made. A house visit doesn’t hold any claims. It’s completely without any obligations. It’s therefore advisable to ask your agent what your position is, should you have a serious interest in the house. This may prevent future disappointments. The same goes for an offer. An offer can be so low that the seller doesn’t feel the need to respond to it. So it’s important to make an offer that triggers negotiations. However, not too high. After all, you don’t want to overpay on your new house.