|-------------7--7-----|
|-------9-9-9--9--9----|
|-------7-7-7--7--7----|*4
|----------------------|
|----------------------|
|---0------------------|
[ Tab from: https://www.guitartabs.cc/tabs/j/john_butler_trio/old_man_tab.html ]
|------------------------------------|
|-------2----------------------------|
|-----------------------2---0--2-----|*4
|-----4---4-----2-----2---2----------|
|---2--------------------------------|
|-------------3-----0----------------|
That basically the start of it.
then during the singing it goes like this.
|-------------7--7-----|
|-------9-9-9--9-------|
|-------7-7-7--7-------|*4
|----------------9-9---|
|----------------7-7---|
|---0------------------|
By the way im only 14 ,so if this is wrong its probablly lack of experiance.