Whether or not you need a financial professional to set up and monitor your ETF portfolio depends on both your particular skills and your inclination to spend a Sunday afternoon getting greasy under the hood. Setting up a decent ETF portfolio is very doable. You can certainly monitor such a portfolio, as well.
A professional, however, has special tools and, hopefully, objectivity to help you understand investment risk and construct a portfolio that fits you like a glove, or at least a sock. A financial planner can also help you properly estimate your retirement needs and plan your savings accordingly.
Do be aware that many investment “advisors” out there are nothing more than salespeople in disguise. Don’t be at all surprised if you bump into a few who express their disgust of ETFs! ETFs make no money for those salespeople, who make their living hawking expensive (often inferior) investment products.
Your best bet for good advice is to find a fee-only (takes no commissions) financial planner. If you are more or less a do-it-yourselfer but simply wish for a little guidance, try to find a fee-only planner who will work with you on an hourly basis.