2) What will they say? . . . Let's answer this question like this. I don't know what they will say, but the courier company is a service organization and you are a customer. You don't care what they say, as long as you know you are going to pack.
3) How can I be sure that what I get is mine? . . . . Generally speaking, if the courier number is correct, you can confirm that this thing is yours. The courier list contains the sender's information, which can be confirmed by phone. The most important thing is that as long as you take the package, if it is not yours, you can find the sender. The courier company will be in a hurry if you take the wrong one. Just wait for them to come to you
And whether I should pay for these things and how much money I should take. . . . This question depends on whether the package you pick up is cash on delivery or prepaid. If you pay in advance, you will have nothing to do. Sign your name, pick up your bag and leave. If it is collect, the courier company will tell you how much freight to pay. If you know which courier company it is, you can check the freight online. General courier companies will charge accurately, and there are few cases of arbitrary charges.
5) In short, there is really nothing to be nervous about taking a courier. Go about your own business and be nervous.