Provide some details. Who received the donation? Was the donation given to a recognized charity? Or did you donate money to an individual who went on the trip?
Donations to charity have their own section on the Deductions and credits paid. How much benefit you get depends on your overall tax situation. Donations are only deductible if they are made to a US exempt organization registered with the IRS, or to a branch of government (which includes public schools) or to a church (some churches are not registered as EOs). If you aren't sure if the recipient was an EO, you can search here.
https://www.irs.gov/charities-non-profits/tax-exempt-organization-search
Gifts to specific people are never deductible, even if they are needy. And gifts from which you benefit are not deductible. If you paid so that your child could go on a field trip, that is never deductible even if the trip is sponsored by an exempt organization. If you paid extra to help someone else, then you must get a letter or receipt from the EO that explains how much you paid, and how much benefit (non-deductible portion) you got.