I have used this code

from odoo import models, fields, api, _

class ResUsers(models.Model):
    _inherit = 'res.users'

    has_logged_in = fields.Boolean(string='Has Logged In', default=False)
    company_id = fields.Many2one('my.company', string='Company')

    @api.model
    def _login(self, db, login, password):

        # Call the original login method
        res = super(ResUsers, self)._login(db, login, password)

        # Check if the user has logged in before
        user = self.env['res.users'].sudo().search([('login', '=', login)])
        if user and not user.has_logged_in:

            # Generate a unique company name using a sequence
            company_name = 'Company %s' % self.env['ir.sequence'].next_by_code('my.company.sequence')

            # Create a new Company
            company_data = {
                'name': company_name,
            }
            new_company = self.env['my.company'].sudo().create(company_data)

            # Update the user's has logged_in and company_id fields
            user.write({'has_logged_in': True, 'company_id': new_company.id})

        return res

Hi,

You can use the following code for creating a new company upon the creation of an account. 

class Account(models.Model):
    _inherit = 'account.account'

    @api.model
        def create(self, vals):
            res = super().create(vals)
            company = self.env['res.company'].sudo().create({
                'name': 'New Company'
            })Replace your name with your desired name of the company 

Hope it helps