You will be able to deduct mileage from your W-2 job to the 1099-MISC coaching job, and from one to another job on your 1040 Schedule C. The mileage deduction for 2017 is 53.5 cents per mile for business miles driven. Attached is a chart to help you with your mileage deductions.
For more understanding on your 1099-MISC mileage deduction and other expenses, please review the follow link: IRS Link