I have been working from home since before Covid19 became a reality.
My primary computer is a Macbook Pro. For windows I have a second computer and I have dedicated virtual machines (VMs) for windows. I have MS office 365, and have been using Office on my Mac for a long time. Most people want MS Office documents/spreadsheets/presentations. While I prefer the Apple Products, I use both. Pick what works best for your needs.
Whether you use a laptop with a monitor or a desktop system a larger monitor is essential. I use a 35" wide screen, it allows three 8x11 views, and is perfect for multiple documents, viewing multiple webpages, or multiple applications at the same time. I also have an iPad, I keep my email open on this so I can quickly see what is coming in. I have the same email configured on the computer, but the iPad serves as a smaller and dedicated second screen. Apple just released an application which allows the iPad to function as a second screen. I use this function 70% of the time.
My monitor is a curved Dell 35.
Keyboard, Mouse -
You have to have something. I prefer using bluetooth and minimizing the wires. I used rechargeable batteries, and have a supply on hand of regular batteries, just in case. (Always keep spare batteries.) I have the Apple keyboard and mouse.
Most laptops have a camera built in. So you don't need to make an investment here. I put my back into a vertical docking station, my camera is not accessible. I purchased an inexpensive (less than $100) USB web camera. It's perfect for video conferencing and works without having to install any software just plug it in. Buy a USB Camera that works without your having to install software. (This is just one more then to break, and you don't need all the fancy settings). I use a logitech knock-off.
These are built-in to my monitor, any set of speakers will work, they don't need to be fancy or expensive. A USB set or DIN Pin setup work fine.
This falls into the category of nice, but not necessary. Many web cameras have a microphone built in. These are usually of poor quality, but will work. You can also use your phone with a headset for dial-in. You can also use a headset and eliminate the need for separate speakers and microphone. I started out with a USB Plantronics headset, upgraded to bluetooth, and then changed to dedicated speakers and stand-alone mic.
My microphone is the Blue Yeti, I love it and it works great. It's great for web-casting also. I also have a Blue Snowball for traveling (it's not small, but it is a little lighter. The Blue Yeti also has a jack for external speakers.
I have a lab for doing consulting work, but this isn't necessary for working from home. I'll talk about this later, but it is work mentioning because it is connect to my NAS Storage.
I have several setups for storage. I have a 1TB external drive for when I travel. I also have a Synology NAS (Network Attached Storage). I put all of the media files, extra files, pictures, and documents on this system. It is redundant and also backed up to Dropbox. I can't afford to lose documents or not have them accessible if I have a system crash.
This is one of the key parts for a home network. I have fast internet 300Mbps down and 15Mbps up. The upload speed is more important than the download because I'm doing so much work remotely. I say more important, because this is the number you want to pay attention to. Providers will typically give you great download, but not a lot of upload.
I have a high quality Ubiquiti Router for home use. My system is a single node Mesh System (not really Mesh, since I only have one node). Mesh stems work by having the router communicate to the other nodes on a dedicated channel, and then the nearest devices connect. They are seamless and use the same Wifi name. This makes roaming from room to room easy and seamless.
If your router is older than 4 years I would invest in one of these. If you aren't technical, get someone to help you, or if you don't need all of the coverage in your house, the cable or phone company router is fine. Make sure you upgrade with them every year.
Make sure you have a comfortable chair. I have a cheap office one from Staples or somewhere. It's adjustable in multiple directions. It's not top of the line, but it works and I've gotten years of use out of it.
Hope all of this information helps.