TikTok new account vs old for changed location

Hello. I will start using US sim card + US VPN for TikTok to reach US audience. Should I create new account using sim card + vpn, or I can use my old account? My old account created in my country (Poland). Also I was added phone number (polish number) to that account, but recently I unattached it. I scary about earlier added polish number to this account, maybe it can cause shadowban if I will change location? Should I create new one, or use old one for US audience? Or maybe it will be better to buy account?