Hi,

first you can create a filed in crm.lead model like 
x_project_id and that is manytoone filed and set reraion model is project.project

and after make automation action in odoo like 

set filter domain as per your work

if record.type == 'opportunity' and not record.x_project_id:

    project = env['project.project'].create({

        'name': record.name,

        'partner_id': project.id})

 automated action code 

this is filed you can create in lead  model 

 i hope it is usefull