If we talk designing from scratch, it will not take longer than 2 months. Site redesigns usually take less than that.
I use WordPress. About 25% of all sites online use this platform. You can easily update/edit content using a visual editor. No programming knowledge required on your part.
5 basic pages: Home, About, Services, Blog, Contact. If you need more, I can add them for a fee.
You only pay for my web design service. Domain registration and hosting is up to you. I can recommend providers for both of the above. If you want, you can subscribe to my maintenance package for added security.
Your website will function without active maintenance which usually takes place once a month. However, there are regular updates released by WordPress which ensure your site is safe from attacks. Apart from installing these updates, I do regular speed checks and downtime reports to make sure all is good.