First time build. Need some advice

From what I can tell you did pretty good with a budget of 1400-1500 bucks.  I only changed two things and really they are small changes.  First I upgraded your ram to 3600 speed ram instead of 3200 because Ryzen processors really benefit from that extra speed and "downgraded" your motherboard to a cheaper 570 board.  Didn't need to pay the extra money for it unless there are some bells on whistles you really want.  I'm assuming you already have your basic keyboard and mouse and monitor.  Otherwise in the searching for a monitor just filter by 144hz, 1ms response time and you should find a lot of options to choose from ranging between 150-200 bucks.

https://www.microcenter.com/site/content/custom-pc-builder.aspx?load=4353149f-7402-4422-9382-5fa3afaad5ea

Yeah the difference in cost between them when compared to performance generally isn't worth it when it comes to the 3700x and 3800x.  It is an easy place to save money and keep near identical performance.  And as for bells and whistles really it's whether or not you want PCIE gen 4 support.  And currently there isn't a whole lot of reason for it because you would have to by a more expensive m.2 drive to even take advantage of gen 4 and graphics cards are all still on gen3.  But if you can get it for the same price with a rebate then I guess you can "future proof" your mobo by having gen 4 support native as for when things do start using it in the next few years.  But that may be another place to try to save money and go with an even cheaper 570 board if you can find one.