Hi,
Adding access rights to your module is for viewing the models , view and menu for the no admin users of the system. If you haven't specified the security for the model you have created default it will be only visible for the super user.
For your module if you need to create a new user group like user in inventory, manager in Project , you can use below code,
<record id="group_test_manager" model="res.groups">
<field name="name">Test Manager</field>
</record>
This will create a new group named Test Manager. Then suppose if you have added your user to this group, we should specify the security for this group users to set to which all models they have access, what all permissions they have, for that we will specify access control in ir.model.access.csv file inside the security folder.
id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink
access_test_model,access.test.model,model_test_model,group_test_manager,1,1,1,1
Once you write the above lines in the ir.model.access.csv file and call the file in manifest file, the users in the group Test group will get access to the model named test_model.
For more refer this blog: Security in Odoo
Thanks