Hi,

Few points to keep in while migrating modules to odoo 14 are listed below:

• If you add new values in a selection field through selection_add, you have to define a new ondelete= attribute setting the value to assign for each previous value in case of uninstallation. More info at https://github.com/odoo/odoo/commit/f0481392c6501cae2c38359f526da1eefa451337. Example: selection_field = fields.Selection(selection_add=[("foo", "Foo")], ondelete={"foo": "set null"}).
• In the XML views, the invisible and readonly attributes no longer support dynamic expressions like state=='draft'. When using those, use the attrs attribute instead. You can only use them for direct context queries like context.get('invisible').
• XML shortcut tags  and  are no longer valid, and must be replaced by its full definition through  tag.
• If there are transient models, you have to add explicit security ACLs for them (and optionally record rules).
• If you were overriding _compute_display_name for getting a different display_name, you should now override name_get method and add there the needed @api.depends. This is not valid though if you want to make display_name stored for allowing a direct name_search. Other option is to override name_search instead.
• Remove size=X attribute in Char fields, as it's no longer valid for restricting the size of the strings.
• _name_search is now returning ids instead of the name_get style tuple (list of (id, display_name)): https://github.com/odoo/odoo/commit/1f48130d2bd055835ee428a21922331d126285a3
• Replace appearances of .with_context(force_company=...) with .with_company(...).
• The access to ir.actions.* objects has been removed, so you need to use sudo or interact via the /web/action/load controller. See odoo/odoo#53335 for more information.

Other the above, install the module directly in odoo 14, and if there is error, fix one by one and go forward until there is no more errors.

Thanks