Yes. A 1099-NEC is considered self-employment. The IRS considers anyone to be self-employed if they are not an employee, i.e. had no employment tax withheld. Age or type of work doesn’t matter.
The taxes are high for a college student because you are paying income tax plus self-employment tax (Social Security and Medicare) because nothing was withheld from your pay.
You can claim ordinary and necessary expenses against your income.