If you're considering a laptop, get a laptop. There's very little downside these days unless you're going for high end gaming or workstation.
Consider the size of SSD. Don't even consider a spinning rust HDD these days unless you're going desktop PC and even then you want SSD for your main drive to host your OS and HDD for large file storage. I'd say go for 512Gb as a minimum rather than 256. For your usage 8Gb RAM is more than adequate but depending on budget 16Gb gives you more flexibility.
Consider the number and type of ports. If you want to drive an external screen, you want USB-C, HDMI or DisplayPort. HDMI is more flexible, i.e can connect to most things, but USB-C dongles are cheap. Most mid range screens these days seem to have USB-C. Cheaper ones may only have DP and/or HDMI. If you are using an external screen, USB-C with power delivery is really useful, you can power your laptop from the screen so only one cable to plug/unplug when you move around. Obviously if you're using external KB/mouse and don't have bluetooth ones, you'll want at least a couple of USB-A sockets too but bear in mind most of the aforementioned dongles have them.
Consider how long you'll be keeping it and whether you'll be likely to (want to) upgrade it. The more portable/thin/light the laptop, the more components are soldered in and not (easily) upgradable. That may not be an issue to you though.
If possible "test drive" the laptop. Laptop keyboards vary massively in quality and ergonomics, as do trackpads. Some are a joy to use, others you will be cursing all the time.
If you're using the laptop screen a lot, it's not nice staring at a poor screen all the time. Personally I can't see the point of 4k on a laptop unless it's 17" or more. Minimum resolution you should consider should be FHD (1920x1080) these days. The sweet spot for me is 2560x1440 or 2560x1600. I'd also want IPS panel (better colours than cheaper TN or VA), although OLED ones are getting cheaper and a step up again in quality.