Hi!
Your forward(self, x) can’t access your conv1 as you didn’t initialize it. To do so, you have to call self.conv1 = Conv2d(...) in the ___init___ method of your model. See here:
    def __init__(self, dropout=None):
        super(Model, self).__init__()
        # in_channels, out_channels, kernel_size, stride=1, padding=0, bias=True:
        self.conv1 = Conv2d(8, 16, 3, stride=1, padding=1) # Changes made here

    def forward(self, x):
        out = self.conv1(x)
        return out