When you get to the end of the Business Expense section, after the specific categories there is a place to put anything that doesn't neatly fit into the previous categories. You can label the custom categories yourself, and enter the amount. Those customized expenses will show up listed on the back of Schedule C, and the total will end up on the front side of Schedule C on Line 27a "Other Expenses."
Also see this IRS Publication for info on Business Expenses:
https://www.irs.gov/pub/irs-pdf/p535.pdfYou mentioned "online training courses." I'm not a tax person, but for tax treatment of "online training courses", you may need to read the following 2 paragraphs that I pasted from that "Business Expenses" publication above:
"You can also deduct the cost of your own education (including certain related travel) related to your trade or business. You must be able to show the education maintains or improves skills required in your trade or business, or that it is required by law or regulations, for keeping your license to practice, status, or job. For example, an attorney can deduct the cost of attending Continuing Legal Education (CLE) classes that are required by the state bar association to maintain his or her license to practice law.
"Education expenses you incur to meet the minimum requirements of your present trade or business, or those that qualify you for a new trade or business, are not deductible. This is true even if the education maintains or improves skills presently required in your business. For more information on education expenses, see Publication 970."
