1. There's something missing from the SSD advice above.
You want an M.2 drive that does "NVME". That will be around 10x faster than a traditional SSD. The
Samsung 970 Pro is currently the best consumer NVME ssd you can get but any NVME ssd will be excellent. Personally I would not get any SSD that lacked NVME right now. Caution: There are M.2 drives that are not NVME capable, and those aren't any better than a normal SATA SSD. Therefore,
the "buzz word" you want to look for is NVME. Some NVME are faster than others, but even the slowest NVME is so blazing fast compared to anything else. NVME is kind of a "game changer" making SLC vs MLC flash mostly irrelevant. The technical detail here is that the CPU gets 4 direct pci express lanes between the CPU and the NVME device. Even the cheapest NVME devices can read or write nearly 1GB/second. That rivals the $20,000.00 FusionIO storage that I use at work (for a couple hundred bucks).
2.
Make sure your laptop has an NVIDIA GPU and at least 2GB dedicated video ram (not shared). This will allow you to enable the "mercury playback engine" in Adobe Premiere. It makes any computationally intensive task significantly faster in Premiere. Effects that might take an hour to apply, may only take a minute or two. Many special effects that require calculation normally can be previewed in real time. Here's a youtube video where some guy compares the two so that you can see the performance difference:
This is not a dig against Intel or AMD GPU's, but I don't believe Adobe supports GPU acceleration with anything other than nVidia. Therefore you must get nVidia. It doesn't really matter much which nVidia GPU you get as long as the laptop has at least 2GB video ram and an nVidia GPU of some kind. You do not have to spend a lot on the latest and greatest. Any nVidia GPU (if it was made in the last 5 years) will do.
3. Ram. As much as you can afford. Consider 8GB the bare minimum, 16GB would be better, 32GB would be better still. RAM is fairly inexpensive these days for desktops, I've got 96GB in the system I use for Adobe CS, but that's not a laptop. Getting laptops with lots of memory capacity can often be difficult and expensive.
4. Thunderbolt 3 port. If you can get a laptop with this kind of port, your laptop will be as up-gradable as any desktop. You can attach external graphics adapters, external storage etc all at very high speed. This is something you might not necessarily use right now but it could keep you from having to replace the laptop in a few years when you want an upgrade. This isn't a must have, but it's a very good idea to have.
5. Colorimiter. This is an external device that plugs into a USB port. It allows you to tune monitors (and televisions). If you have a colorimiter, you could connect a 4k TV to your machine and adjust the color on it. You wind up with a very inexpensive high quality display since most 4k tv's also support wide color gamut. You can get a colorimeter for around $100 and no mater what kind of display you use (even the built-in laptop display) this thing will be your best friend. I use this one (it's discontinued)
https://www.amazon.com/ColorVision-...er+datacolor&qid=1553709528&s=gateway&sr=8-12 . Under $100 on Amazon. Even a colorimeter this old will work very well. The newer ones are generally better but the old ones get the job done nicely and won't break the bank
Edit: Whoops.. I'm out of date. Premiere supports OpenCL now in addition to CUDA. That means you should be able to use just about any nVidia, AMD, or Intel graphics adapter for HW acceleration.