You probably don't need an LLC for liability reasons. There are two types of liability an LLC could protect you from. Tort liability (e.g., getting sued because you injured somebody in the course of or because of your work) or contractual liability (getting sued because you don't fulfill a contractual obligations related to the business). For tort liability, if you don't carry sufficient insurance, a court will "pierce the corporate veil", meaning the court will ignore the fact that you ahve an LLC and hold you personally liable because you didn't adequately capitalize or insure your business. For contractual liability, anybody relying on you to do something financially significant will probably require you to personally guarantee the contract anyway.
That said, if you live in a jurisdiction where it is cheap to maintain, it does provide some protection and potentially simplifies the sale process in the event you sell. It's also possible it would allow you to do some tax optimization, although I'm less sure about what's available if you do a simple LLC as opposed to an SCorp.