First time here. I completed almost 4 weeks with neither WiFi nor Ethernet; I'm using USB tethering for internet connection. I've followed several tutorials and solutions posted in forums but I've been unable to solve my problem hitherto. I'd really appreciate some guidance from scratch i.e. diagnosis, troubleshooting.

Operating System: Ubuntu 20.04.1 LTS

*-network UNCLAIMED
description: Ethernet controller
product: RTL810xE PCI Express Fast Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:02:00.0
version: 07
width: 64 bits
clock: 33MHz
capabilities: bus_master cap_list
configuration: latency=0
resources: ioport:d000(size=256) memory:ef200000-ef200fff memory:e2100000-e2103fff
*-generic DISABLED
description: Wireless interface
product: RTL8821AE 802.11ac PCIe Wireless Network Adapter
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlp3s0
version: ff
serial: f0:03:8c:ac:4a:27
width: 32 bits
clock: 66MHz
capabilities: bus_master vga_palette cap_list ethernet physical wireless
configuration: broadcast=yes driver=rtl8821ae driverversion=5.4.0-48-generic firmware=N/A latency=255 link=no maxlatency=255 mingnt=255 multicast=yes wireless=IEEE 802.11
resources: irq:130 ioport:c000(size=256) memory:ef100000-ef103fff
description: Ethernet interface
physical id: 1
bus info: usb@1:2
logical name: usb0
serial: 72:de:96:42:06:a1
capabilities: ethernet physical
configuration: broadcast=yes driver=rndis_host driverversion=22-Aug-2005 firmware=RNDIS device ip= link=yes multicast=yes
WARNING: output may be incomplete or inaccurate, you should run this program as super-user.

I don't know whether this initial information is enough. TIA!