*To be clear, these parts are just my personal choices going by what I've owned and haven't had issue with. If you don't like it, that's fine, just move a long or suggest better parts for better prices.*

So keeping it under $3,000 new can be done, but it will hinder performance a bit, but if you're not to hard up on playing above 1080p and don't mind being below Ultra on the settings you can get something fairly decent.

Ryzen 7 7800X3D - $400 - Solid CPU with excellent gaming performance and shouldn't be a bottle neck for many games.

ASUS TUF B850 Wi-Fi - $200 - Decent mid tier mother board with Wi-Fi if you need it, and multiple M.2 slots for adding more storage if you need.

Corsair Nautilus 360 AIO - $100 - 360mm AIO cooler for $100 is a great price. A bit overkill for your cooling needs, but if you ever decide to upgrade your CPU it doesn't hurt. You could go with an air cooler and be just fine also, but a decent one is going to cost a pretty penny.

Corsair Vengeance 32GB 6000 mt/s CL36 - $450 - It's not the fastest memory, but it's more than enough for what you want to do. I would personally go with 64GB as it really seems like the new standard, but with RAM prices what they are now it's not worth it.

Samsung 990 EVO 2TB - $380 - Quality NVME storage drive with enough space for you to get by on a single drive. It's a bit on the pricy side, but I've personally never had an issue with Samsung drives. Ideally you'll want a separate drive, either a smaller one for Windows, or a larger one to store your games on, but you can get by running a single drive.

ASUS 5060 Ti Dual - $580 - Slightly below mid tier GPU, but it does have 16GB of vRAM and will work just fine for most 1080p gaming. If you can swing it I would personally go with a 5070 Ti just to future proof, but this will be more than enough. For reference an ASUS TUF 5070 Ti is $1,070. This would put you close, or a bit over, your $3,000 budget, but give you much better performance on higher settings.

Corsair RM850e PSU - $130 - Good quality power supply at a good price that should leave you plenty of room should you choose to upgrade down the road.

NZXT H6 Flow - $90 - Great mid tower case with plenty of air flow, support for large AIOs and GPUs, and a semi dual chamber design giving you lots of room in the back to run wires and work in.

Noctua NF-A 120mm Fans - $130 - Great quality 120mm fans, just in an ugly color. Comes in packs of 2 fo $65 so I added 2 to the list.

Thermal Grizzly Kryonaut - $10 - Excellent thermal paste. AIOs generally come with thermal paste on the block, and are good, but it never hurts to put some quality stuff on to help with heat transfer.

So this build comes in at $2,500 before shipping and tax. I've no idea what the taxes are like where you are, or if you have a PC store close where you could buy the parts and save on shipping. That leaves you a bit of money left over to either look at upgrading these parts, or just save some money. I would personally consider the GPU upgrade, but that's just me.

As for building, it really is easy now days. A lot of guides online can easily help you build it, as most of it is literally plug and play. Diagnosing issues that might arise on your first start up may require you to come back and ask for help, or a bit of google work, but it really isn't all that bad.