How do I report roadside income on home grown citrus sales on my federal tax return?

That is a business with sales, expenses and cost of goods sold.

You need to complete Schedule C to report all that. If you show a profit, you will need Schedule SE to calculate the self-enployment tax.

These forms are submitted with Form 1040.

Do you have any wage income in addition to self employment?
If so, and the sales aren't much, you can add the income under misc income.
Otherwise you fill out Schedules C and SE in addition to the long 1040.
You check the box for sole proprietor and use your own name and SSN. You can be you 'doing business as Joe's Fruit' if you want. You don't want to deal with being an employer yet, which is a lot different.
C is for deductions, such as materials to build the stand, advertising and signs, paper bags - anything you kept receipts for.
SE is self employment tax, for your future Social Security.