I downloaded/installed the latest version of Kubuntu a few days ago as my main OS. My only issue is that my PC can't find any wifi networks in the area. I'm using an ethernet cable connection(which isn't convenient) right now and an HP laptop. Since every "remedy" I found contains either fancy terminal commands or installing some drivers I don't know where to get, it seems I'm stuck. I'm confused on what to do next. A last resort would be to maybe get some external wifi adapter, but then I found this forum. Is there any important information specific to my computer I need to provide? Thanks for your help.

Without some more info about your system, especially the wifi card's info, it is hard to determine what to do.
But it will involve some command line work, at least for informational purposes. Nothing fancy, though.

the output of the command lspci will give some useful info you can copy and paste

As this is not a Plasma specific issue, you likely will get better info on Kubuntu's forum.

This is what I got as a result:

00:00.0 Host bridge: Intel Corporation Device 31f0 (rev 03)
00:00.1 Signal processing controller: Intel Corporation Celeron/Pentium Silver Processor Dynamic Platform and Thermal Framework Processor Participant (rev 03)
00:00.3 System peripheral: Intel Corporation Device 3190 (rev 03)
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 605 (rev 03)
00:0e.0 Audio device: Intel Corporation Device 3198 (rev 03)
00:0f.0 Communication controller: Intel Corporation Celeron/Pentium Silver Processor Trusted Execution Engine Interface (rev 03)
00:12.0 SATA controller: Intel Corporation Device 31e3 (rev 03)
00:13.0 PCI bridge: Intel Corporation Device 31d8 (rev f3)
00:13.2 PCI bridge: Intel Corporation Device 31da (rev f3)
00:13.3 PCI bridge: Intel Corporation Device 31db (rev f3)
00:14.0 PCI bridge: Intel Corporation Device 31d6 (rev f3)
00:14.1 PCI bridge: Intel Corporation Device 31d7 (rev f3)
00:15.0 USB controller: Intel Corporation Device 31a8 (rev 03)
00:17.0 Signal processing controller: Intel Corporation Device 31b4 (rev 03)
00:17.3 Signal processing controller: Intel Corporation Device 31ba (rev 03)
00:1f.0 ISA bridge: Intel Corporation Device 31e8 (rev 03)
00:1f.1 SMBus: Intel Corporation Celeron/Pentium Silver Processor Gaussian Mixture Model (rev 03)
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
05:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723DE 802.11b/g/n PCIe Adapter

Hi!
In order to install the wifi drivers, you need to install some other packets first.
sudo apt install build-essential git dkms linux-headers
Download the driver with
git clone https://github.com/smlinux/rtl8723de.git -b 5.0-up
Install it with
sudo dkms add ./rtl8723de
Reboot

Thanks for your answer! I put the following command into the terminal as you said: sudo apt install build-essential git dkms linux-headers
It gives me a long list of different packages and asks me to select one:

Reading package lists... Done
Building dependency tree
Reading state information... Done
Package linux-headers is a virtual package provided by:
linux-headers-5.0.0-1037-oem-osp1 5.0.0-1037.42
linux-headers-5.0.0-1033-oem-osp1 5.0.0-1033.38
linux-headers-5.0.0-1030-oem-osp1 5.0.0-1030.34
linux-headers-5.0.0-1025-oem-osp1 5.0.0-1025.28
linux-headers-5.3.0-40-lowlatency 5.3.0-40.32
linux-headers-5.3.0-40-generic 5.3.0-40.32
linux-headers-5.3.0-29-lowlatency 5.3.0-29.31
linux-headers-5.3.0-29-generic 5.3.0-29.31
linux-headers-5.3.0-26-lowlatency 5.3.0-26.28
linux-headers-5.3.0-26-generic 5.3.0-26.28
linux-headers-5.3.0-24-lowlatency 5.3.0-24.26
linux-headers-5.3.0-24-generic 5.3.0-24.26
linux-headers-5.3.0-23-lowlatency 5.3.0-23.25
linux-headers-5.3.0-23-generic 5.3.0-23.25
linux-headers-5.3.0-22-lowlatency 5.3.0-22.24
linux-headers-5.3.0-22-generic 5.3.0-22.24
linux-headers-5.3.0-19-lowlatency 5.3.0-19.20
linux-headers-5.3.0-19-generic 5.3.0-19.20
linux-headers-5.3.0-1013-azure 5.3.0-1013.14
linux-headers-5.3.0-1012-gcp 5.3.0-1012.13
linux-headers-5.3.0-1012-azure 5.3.0-1012.13
linux-headers-5.3.0-1011-gcp 5.3.0-1011.12
linux-headers-5.3.0-1011-aws 5.3.0-1011.12
linux-headers-5.3.0-1010-kvm 5.3.0-1010.11
linux-headers-5.3.0-1010-azure 5.3.0-1010.11
linux-headers-5.3.0-1010-aws 5.3.0-1010.11
linux-headers-5.3.0-1009-oracle 5.3.0-1009.10
linux-headers-5.3.0-1009-kvm 5.3.0-1009.10
linux-headers-5.3.0-1009-gcp 5.3.0-1009.10
linux-headers-5.3.0-1009-azure 5.3.0-1009.10
linux-headers-5.3.0-1009-aws 5.3.0-1009.10
linux-headers-5.3.0-1008-oracle 5.3.0-1008.9
linux-headers-5.3.0-1008-kvm 5.3.0-1008.9
linux-headers-5.3.0-1008-gcp 5.3.0-1008.9
linux-headers-5.3.0-1008-azure 5.3.0-1008.9
linux-headers-5.3.0-1008-aws 5.3.0-1008.9
linux-headers-5.3.0-1007-oracle 5.3.0-1007.8
linux-headers-5.3.0-1007-kvm 5.3.0-1007.8
linux-headers-5.3.0-1007-azure 5.3.0-1007.8
linux-headers-5.3.0-1007-aws 5.3.0-1007.8
linux-headers-5.3.0-1006-oracle 5.3.0-1006.7
linux-headers-5.3.0-1005-gcp 5.3.0-1005.5
linux-headers-5.3.0-1004-kvm 5.3.0-1004.4
linux-headers-5.3.0-1004-azure 5.3.0-1004.4
linux-headers-5.3.0-1004-aws 5.3.0-1004.4
linux-headers-5.3.0-1003-oracle 5.3.0-1003.3
linux-headers-4.15.0-1067-oem 4.15.0-1067.77
linux-headers-4.15.0-1066-oem 4.15.0-1066.76
linux-headers-4.15.0-1065-oem 4.15.0-1065.75
linux-headers-4.15.0-1059-oem 4.15.0-1059.68
linux-headers-5.3.0-18-lowlatency 5.3.0-18.19
linux-headers-5.3.0-18-generic 5.3.0-18.19
linux-headers-5.3.0-1004-gcp 5.3.0-1004.4
linux-headers-5.3.0-1003-kvm 5.3.0-1003.3
linux-headers-5.3.0-1003-azure 5.3.0-1003.3
linux-headers-5.3.0-1003-aws 5.3.0-1003.3
linux-headers-5.3.0-1002-oracle 5.3.0-1002.2
linux-headers-4.15.0-1050-oem 4.15.0-1050.57
You should explicitly select one to install.

E: Package 'linux-headers' has no installation candidate



How do I chose the correct "installation candidate" and how would I write that as a command? Thanks!