See the joining documents, usually notice period applies after sometime. If u r joining new co. on Monday, let gp know ur resignation via email and inform them that you will visit to clear any formalities. If it requires u to pay a month’s salary, do it and don’t burn the bridge. Who knows u meet gp later in career.
If ur PF acc is created already or whatever it will be taken care of in new co. it’s a usual thing for finance/HR/PF.