LioHernandez :
I'm building a PC for the first time so can someone please help me with this build? (I'm going to use it mainly for gaming)
Here it is
CPU: Intel Pentium G4560
GPU: Radeon Rx 470 (4GB)
Motherboard: B250M PRO-VD
RAM: Avexir 8GB (2 x 4GB) DDR4-2400
HDD: 1TB Western Digital Blue
PSU: SeaSonic M12II 520W 80+ Bronze
System: Windows 10 64-bit
Is this build a good build? Can it play the latest games at high quality with at least 50+ fps?
Are Avexir ram's good ram's? And should i choose 2x4GB rams or 1x8gb rams for gaming?
Are Seasonic psu's good psu's? Also should i choose S12II or M12II ?
Should i get the WD Blue HDD or the Seagate Barracuda HDD ?
Is this build a good build? Can it play the latest games at high quality with at least 50+ fps?
It's a good basic "step-up/upgradable" build, not the best build (yet), but a good foundation to step up to a more powerful i5 or i7 CPU. That Pentium G4560 is one of the best price/performance entry-level CPU as it is 2-core but with hyperthreading (4-thread), giving the more expensive i3-6100 a run for its money.
In terms of 50+ fps on high settings, that entirely depends on the gaming system requirements and your gaming resolution. If you are talking about CPU/GPU-demanding games, then, no it won't reach 50 fps on high on 1080p-resolution (you might have to lower the graphics settings to get acceptable framerates). The RX 470 is a good mid-range GPU for 1080p and may pair nicely with that Pentium G4560 on most games at basic settings. Top of the line GPU's (RX 480 / GTX 1060 / GTX 1070 and up) may be hindered in its max. possible performance by the weaker CPU. You should only consider those high-powered GPUs if you are ready to upgrade your CPU to an i5 or i7.
Are Avexir ram's good ram's? And should i choose 2x4GB rams or 1x8gb rams for gaming?
There are fine, though not the most sought-after brand such as G.Skill or Corsair or HyperX. The 8GB RAM is considered minimum nowadays. Some selected games benefit from 16GB RAM but for a budget build, the 8GB would run most games a-okay. Getting a 2 x 4GB would take advantage of the dual channel (faster speeds) your motherboard offers, but, since you selected a motherboard with only 2x RAM slots, upgrading those RAM later on would mean purchasing new RAM sticks. Getting a 1 x 8GB RAM now would give you the opportunity to add another 1 x 8GB later on for a total of 16GB. However, there *might* be incompatibilities in adding another RAM stick (even of the same brand/model/speed/etc) as those 2 RAM sticks were not tested and sold as a pair. If you don't plan on upgrading the RAM to 16GB for a long time, then, get the 2 x 4GB.
Are Seasonic psu's good psu's? Also should i choose S12II or M12II ?
Yes, one of the best PSU manufacturers. The S12II and M12II are generally the same, with the exception of how the cables were designed. The S12II is non-modular, meaning, all cables are attached to the PSU; the M12II is fully-modular, meaning, all the cables are detached and you can select the only cables you need to be attached on the PSU. The fully-modular PSU's are good for eliminating the cable clutter inside the case, improving both aesthetics and airflow. But this entirely depends on how your case was designed. Some cases have its PSU on a separate chamber or with a PSU shroud/cover so much that getting the non-modular cable for a lower cost will seem to be logical.
Should i get the WD Blue HDD or the Seagate Barracuda HDD ?
Get the cheaper one. I personally use WD and have not failed on me yet (I haven't used Seagate). Both HDDs are pretty much the same speed / capacity / warranty / etc.