When installing the motherboard, do NOT over tighten the screws! The motherboard is made up of several layers with circuitry on each one. Do not crush them together. Just tighten them until firm. This is not the time to prove how strong you are, be smart.
Keep track of all your parts and accessories. That rattling noise is going to free the magic smoke if you plug it in before fixing it. And take the time to double check your motherboard standoffs. Totally unrelated to that rattling noise...
You may be greeted with a driver disk when you open your GFX card or motherboard. Those drivers are usually obsolete before you open the box. Download all of your necessary drivers the day before you're going to build your first PC. This step gets you familiar with your hardware and the resources the manufacturers offer and it may even spur a question or 3 you hadn't thought of such as where do I download my internet drivers. The majority of your necessary drivers come from the motherboard's manufacturer. The GFX card will also need specific drivers that come from Nvidia or AMD.
What warranty coverage comes with the hardware and what are your responsibilities? It's been two years since you built your rig and you're enjoying a gaming session when your GFX card fails. Who do you contact? Can it be replaced for free even after store's return window closes?
start with a nice large work bench make sure there no carpet under it to make a static charge. have a good led flashlight and one screwdriver (+) tipped that magnetic to keep the mb screws from failing inside the case or power supply. make sure the pc your making a windows boot usb stick from is clean of virus. with a good led flashlight look at the cpu and cpu slot for any smashed pins. with the mb out of the case put the ram and cpu and cooler on. pre fit the mb make sure the eps cable will reach.
2. Research is good. The CPU hierarchy has some uses. Ask the forums here for a second opinion. Experienced advice for one's needs are an invaluable resource.
3. Now that 3 has been corrected. I'd further correct it. It would be better using the stock heatsink. Rather than the added headache of finding an aftermarket heatsink with pre-applied thermal paste. Save the aftermarket heatsink for when you are ready to experiment with thermals, noise and overclocking. If you feel it may be the next step. Buy a Ryzen which includes a heatsink. Then you can overclock later and add an aftermarket cooler later.
4. If you aren't sure. Check the vendor list for the motherboard or ask the people here in the forums.
8. Mid-sized Philips is vague. It should be a #2 Philips. That is the most common type used.
1. The main part: Read instructions, even after 40+ years I download and carefully read them BEFORE I acquire any HW. Makes it easier to choose components and assemble later on. Relaying on colorful self praising adds doesn't tell whole story.
Most manuals tend to be translated by blind monkeys, so consult forums in local language if possible.
2. Actual parts never look same as on manufacturer's site pictures.
3. Watch out for those pesky MB spacers, they are rarely set for your MB. Every other or third problem comes from that. White smoke (even if invisible) is usual result.
3. Smoke test (first plug in and switching on of power, don't do it in dark and when tired or sleepy, recheck everything ten times !!!
4. Keep main power cable away as far as possible until ready to turn on first time !! Any power to PSU when assembling components can result in sparks and that obviously don't go well with electronics. Coffee, tea or flick of your Bick, keep in another place, drinking and assembling computers don't go well together.