I have the pattern, it must have been offered for free at some point.
Notice that each box is 5 sts X 5 rows. That can help make counting easier, as already stated. The bold lines are also good for helping with counting and seeing exactly where you are on the chart.
Your cast on is 104 sts. The chart is 26 sts, 104/26=4, That means that you will work across the chart and go back to the beginning of that row of the chart another 3 time per round. You can use stitch markers to separate whatever portion or portions you choose, that is one after every 26 sts or other spots that seem logical to you. That can help to see where you are in the chart too. Keep count of your rounds - I like to use a stitch marker that I advance one stitch each time I come to it but whatever works for you. Mark off either on the chart or somewhere else when you finish a row so at a glance you know where to pick it up again when you come back. That’s all I can think of now.
You can do this! If you run into problems be sure to ask. Just don’t let yourself get too frustrated with it. Even something pretty simple when you do it the first time can be challenging.