@up_1
Please follow the below suggested actions:
Method1(Efficient Method):
1. Launch Excel file
2. Use "Get First Free Column/ Row from Excel worksheet" and get firstfreecolumn number
3. then use "Write to Excel worksheet" action to insert new column in left side of last column "Name"
4. Repeat same action one more time to insert another column named as "Age"
5. Save the Excel


Code:
Excel.LaunchExcel.LaunchAndOpenUnderExistingProcess Path: $'''Y:\\Accounts_Details.xlsx''' Visible: True ReadOnly: False Instance=> ExcelInstance
Excel.GetFirstFreeColumnRow Instance: ExcelInstance FirstFreeColumn=> FirstFreeColumn FirstFreeRow=> FirstFreeRow
Excel.WriteToExcel.WriteCell Instance: ExcelInstance Value: $'''Name''' Column: FirstFreeColumn Row: 1
Excel.WriteToExcel.WriteCell Instance: ExcelInstance Value: $'''Age''' Column: FirstFreeColumn + 1 Row: 1
Excel.SaveExcel.Save Instance: ExcelInstance
Method2(Not Preferred- We can't create with specified column name):
1. Launch Excel file
2. Use "Get First Free Column/ Row from Excel worksheet" and get firstfreecolumn number
3. then use "Insert column to Excel worksheet" action to insert new column in left side of last column
4. Repeat same action one more time to insert another column
5. Save the Excel

Code(Copy and Paste the below code in your PAD designer screen):
Excel.LaunchExcel.LaunchAndOpenUnderExistingProcess Path: $'''Y:\\Accounts_Details.xlsx''' Visible: True ReadOnly: False Instance=> ExcelInstance
Excel.GetFirstFreeColumnRow Instance: ExcelInstance FirstFreeColumn=> FirstFreeColumn FirstFreeRow=> FirstFreeRow
Excel.InsertColumn Instance: ExcelInstance Column: FirstFreeColumn - 1
Excel.InsertColumn Instance: ExcelInstance Column: FirstFreeColumn - 1
Excel.SaveExcel.Save Instance: ExcelInstance
If I've successfully resolved your queries, please consider accepting this as the solution and giving it a thumbs up. Your feedback is greatly appreciated!