HP Pavilion-CS3006TX Wifi, Bluetooth, Sound, Display drivers not working Ubuntu 18.04

[rookhallow]

I bought a new HP Pavilion 15 CS3006TX today, and I wanted to install Ubuntu 18.04 LTS on it alongside Windows 10. However, it came with multiple setbacks.

Firstly, the laptop has an Nvidia graphics card on it (Nvidia MX250 2GB), which meant I had to boot the installer using the `nomodeset` setting in grub, which I had never used before. This took a lot of tinkering to get right, as, for some reason, when I disabled secure boot, the Ubuntu installer didn't boot up and showed me a blank screen until I force shut it down, and it only worked when I enabled secure boot. Weird!!!

After all this, I finally reached the installer. I never got an option to select a WiFi network as my WiFi adapter wasn't detected by Ubuntu, and so I installed Ubuntu without many important components (especially build-essential, make, ifconfig, etc. which are absolutely essential).

Finally, after this half-baked Ubuntu installed, I tried to change the brightness, which didn't work, the sound didn't work, and as I said before, the WiFi, and now, the Bluetooth weren't working.

So, I started digging around the internet, and I've been here, here and here trying to get my Realtek 8168 adapter to work. I think this is just an Ethernet driver though, which is working fine, btw, and I've checked it thoroughly. However, the solutions posted in the above links didn't help me out much, and I'm still not able to use WiFi (or Bluetooth).

Next, I also need my sound and display brightness settings to work as expected... Any pointers on that would be greatly appreciated. Please, please help me out... I'm in a sticky situation and truly need help.

(Some specs of the laptop: 256 GB SSD + 1 TB HDD, Intel Core i5-1035g1 (10th gen), 8 GB RAM, and 2 GB Nvidia MX250 graphics)