Building a new PC

[Sooner535]

Hello, first let me say I am not 100% fluent when it comes to PC work, I have picked up a lot but I usually stay away from general talks about components and the likes. With that said I would like to build a new PC, my old one is extremely dated and I could use a new one. Here would be the following requirements:

Under 3,000$ (with shipping included)
Little to no maintenance
Would like to be as close to top line as possible so I don't have to get a new one for a long time, so if it needed to creep over 3k, then that is fine.
I want to connect my PC to my (eventual) new TV, I plan to go for a 70ish inch TV, not a 4k but a HD one, so I imagine a bigger TV needs more powerful components since it is displaying more?

Anyways could someone help me pick out good parts and give me ideas on how to build one correctly? I have a few questions about the whole thing too:

Wiring, can someone give me advice on this? Especially when it comes to the PSU to things? If it's a 4-prong connector, and my GPU and CPU uses a 4-prong one, can it connect to either? Or are there certain rules for that?
When it comes to fans and the like, how often should you air clean the PC?
Why do multiple companies make GTX 1080s for example, which ones are good? What are the bad companies when it comes to components?


Thank you to anyone who helps, I really appreciate it

 

[WildCard999]

Quick question about my build that I didn't think of until now:

How am I going to use my headset on it? Will I need a DAC or Audio card at all? Will the motherboard picked be acceptable in audio output? Also will I need a internet adapter card thing? Or is the motherboard good?

The built in audio in the motherboards nowadays is really good, try it out first before considering a audio card. As for the internet connect it via Ethernet cable.