Greetings Sir or Madam and welcome to JA! I will do my very best to assist you with your problem.
Based on your description it is likely a bad connection between the starter and the battery. I would have the charging system tested and the battery however. It is most likely a poor connection though. Most parts stores like autozone can test the battery and the alternator right on the car and will do so at no charge.
This is where I would start. Hope it helps!