I built my main desktop computer for less than $300 USD. It has an Intel Core i5-4690K CPU, 16GB of DDR3 RAM clocked at 1600MHz, an RX 470 graphics card, and several hard drives that I got for cheap. The case that I have is a Thermaltake Versa H21. It was fairly cheap and has plenty of room for expansion. My main PC does everything I need it to do, so I have no reason to upgrade. Despite the fact that the CPU and GPU are around a decade old, they still perform quite well. I have Linux Mint installed on my main PC.
I have a secondary desktop that I use specifically for gaming. I built it for around $220 USD. It has an Intel Core i5-4590, 8GB of DDR3 RAM clocked at 1600MHz, a GTX 980 GPU, and a 1TB SATA SSD that I got in early 2023 when SSD prices were dropping. My gaming PC doesn't get much use nowadays. There are a couple games that struggle on my gaming PC, so I'll likely upgrade it within the next year-or-so. I'll probably get an Intel Core i7-4790K and 16GB of RAM. Those upgrades would only cost about ~$80 as of writing this, and would provide a substantial increase in performance. I have Windows 10 installed on my gaming PC because there are a few games that just don't work on Linux.
The main laptop I use is a ThinkPad X280. I got it used on eBay for $100. It has a 7th gen i5 processor, 8GB of RAM, a 512GB NVMe SSD, USB-C charging, decent port selection, and good enough battery life. The screen is 1366x768, which isn't a deal breaker for me, but something worth noting. There's basically zero upgradability with this laptop. It lacks an ethernet port which is annoying. The X280 is pretty snappy thanks to the fairly modern processor, and it can handle all the things I do on a laptop. I'd recommend getting the T480 instead of the X280 because it has a higher screen resolution, replaceable battery, and an ethernet port. This laptop is quiet most of the time. The fan only spins up if you have too much stuff open at once (several tabs in a couple different browsers + a couple other programs open). For the price, I'm happy with the ThinkPad X280. I have Linux Mint installed on my laptop.
I currently have a Google Pixel 7. I would not own this phone if I didn't get it for free. It's alright. I cannot flash my own custom rom on it due to the phone being OEM locked, which is annoying. It also doesn't have a headphone jack. I don't really use my phone enough to care about the cons. That said, I'd get some cheap android phone that I can put a custom rom onto if I didn't get this phone for free. If you're going to buy a Google Pixel, buy one that is OEM unlocked, and buy the "a" series of Google Pixel phones. They are much cheaper without sacrificing too much.
Typically I try to use FOSS software as much as possible. The software I use might not be perfect, but it works for me.
For school I use the Brave browser. It's basically Google Chrome, just without all the Google spyware. I don't really have any issues with it as of now. For everything else, I use Librewolf. I don't really have any major issues with it either, but I wouldn't recommend it to normies. It's great for privacy-oriented people. Most web browsers suck, but I've found that Librewolf and Brave are the most tolerable.
I've used several Linux distibutions the past few years. I've settled on Linux Mint. It "just works" for me right out of the box. I don't have to do any major customization after re-installing my OS. I started using Ubuntu in 2022, and Mint later that year. I did try out a few other distro's but kept coming back to Mint. Really any Linux distro is fine, just find one you like.
qBittorrent. I tried using Transmission. It sucks. qBittorrent is great.
I recently started using Mullvad VPN. It only costs ~$5 USD/mo. You can pay using cryptocurrency, which is very nice (You even get a 10% discount for paying with crypto). You don't have to give them your email or anything, you're just given an account number when you create an account. If someone somehow finds your account number, you're in trouble. Mullvad is great but do your own research when choosing a VPN. I route pretty much all of my Internet traffic through a VPN.
I just use VLC for almost everything. It does the job. Rhythmbox comes pre-installed with Linux Mint, so I use that as my music player. It's pretty good.
Handbrake is a great piece of software for compressing video files. I believe Handbrake is FOSS. k3b is a FOSS program that allows you to burn content to CD/DVDs. Steam works on Linux but I'd highly suggest you obtain games elsewhere. Most games work on Linux now thanks to Proton. OBS Studio is a FOSS way to record your screen, although it has become increasingly bloated with each new update. YT-DLP is the best tool to download YouTube videos.