Yeah, sorry, $HOME is a special variable that points to the user's home directory. There are other similar to this one like $USER that resolves to the username itself, etc.
That's good news, it probably means that is using the SMB protocol which is very common for Windows machines. So let's tackle both questions:
First, you can instruct the system to mount it automatically by adding a new entry to the /etc/fstab file. It's nearly identical to that command from the command lihould look something like:
//192.168.1.10/data /home/zenzen/testing_share cifs credentials=/home/zenzen/.smbcred 0 0
Notice that in this file you need to specify the full path to where you want to mount those files i.e. you cannot use variables like $HOME.
Related to your second point (if I understood correctly), instead of providing the username/password directly to this command, you can point to a file somewhere in your system that contains this information.
You can create this file in the same way you did with the secrets file for the dav2fs package earlier. For example, create a hidden file in your user directory called .smbcred with the following lines:
username=
password=
And lock it down so that only you can read/write to it:
chmod 600 /home/zenzen/.smbcred