The code returns each Parameter of your model.
What do you mean by “first row of each individual tensor”?
Here is a small example:
model = nn.Sequential(
    nn.Conv2d(3, 6, 3, 1, 1),
    nn.ReLU(),
    nn.Conv2d(6, 12, 3, 1, 1)
)

for child in model.children():
    for name, param in child.named_parameters():
        print(name, param[0])

> ('weight', tensor([[[...]]])
> ('bias', tensor(...)
...