Yes, a low score when checking in for a goal means that you're not doing well progressing towards your aims. A low score will trigger an alert to your community platform team and your goal buddy will be in touch to offer you one to one help and advice.
By joining a goal, you're consolidating the connection to your community - struggling to meet your goals is nothing to be ashamed of, everyone needs a little help from time to time and the goals feature is here to help.