@legento Awww new PC building time is the best! If I was that side of the world I would assist for sure haha. But don't doubt yourself man, it's kind of like lego or connect the dots or that thing the kids do where they put square pegs in square holes haha.
New PC build is easier than rebuilding it the 5th time and half the standoff screws are missing haha. I would say if you don't come right finding assistance, give it a shot with some youtube assistance.
Basically the only thing you have to pay attention to is putting the CPU onto the mobo. Just make sure you line it up correctly then lower it into position and drop it in. Never push the CPU. Other than that, it's fun and games looking through the manual haha.
Steps are as follows:
1. Put your standoff screws to match the mobo screw holes into the case
(look for little circles around a hole with little metal stripes, should be one on the top left by top usb port for an example)
2. Put the mobo IO/shield into the case.
3. You can now add the PSU and HDD/SSD.
4. Next put the mobo in, you have to lay it down on then push it a bit towards the ports to get it to line up nicely.
(only tighten screws a bit until they are all in then go back and fasten them all, this allows you to adjust a bit).
4. Once the mobo in in, put the CPU in. just follow instructions and go slow and steady. Should be just unhinge, align and lower.
5. Add the cooler, should come with thermal compound on it so just remove the plastic, lower it and screw it in. Tighten screws on the cooler a few turns at a time then go across the cooler to the next one in like a zig zag pattern (apparently better to pressure the compound evenly but so far I've realised that this is less important than my pedantic ass thought).
6. Now screw in various fans. You only reealllyy need the one at the back blowing out but add as many as you feel suits you.
Note: if you add more, try balance push/pull i.e. on in the front blowing in to match one blowing out the back and maybe one blowing in the bottom and one blowing out the top. You can tell which way a fan blows by looking at the shape of the fin (it looks like a scoop, the scoop pushes the air, thus the side where it concaves in, that side is the blowing direction. Also, the cool stickers are normally on this side. Sometime they indicate the direction. I have found fan screws to be the most difficult to get in, just have to keep retrying and push a little bit sometimes.
7. Connect the PSU to the mobo via the 24pin big connecter and the 8 pin CPU connecter, try route them through the case layout for neatness. Only cable tie once the main ones are all in. After this I like to connect the PSU to the wall, I've heard it helps ground the system, just leave it switched off.
8. Add your RAM just check which side of the notch goes up, one is side is shorter. Just don't touch any golden looking connecter parts. This goes for everything. Some don't care about that as much as I do.
9. Some might recommend only adding your GPU after everything but I add it now and haven't had issues. Just push it in the top PCIe slot gently but firmly until it locks in. again, don't touch the golden connector part. Connect the GPU to the PSU, should need the 8 pin VGA power, so line the 2+6 up and connect.
10. Now connect your PSU to the HDD/SSD (and DVD drive if you have one) then connect their SATA cables to the mobo, look for the SATA6G connections, they are fastest use them first for your boot drive.
11. Connect all the front panel cables like start/reset button, USB header and audio (the audio might have two types on one, mine has AC'97 and HD audio (the latter is the latest). Also connect all fans, make sure the CPU fan is connected to the CPU fan connection on the mobo, there will be a specific one.
If I haven't forgotten anything (maybe other pros can double check me here) that should be it. Sounds like a lot, and the first time you do it takes a few hours but it's really rewarding getting it done and not as complicated as one might imagine. If in doubt, just follow instruction and then youtube/google.
Otherwise, enjoy the system man. Looks like a very formidable machine and I'm sure you will enjoy it for a long time still. Don't give in to the CUD too soon!