How can I connect power plug and two 4k monitors to MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports)?

As Grant Bennet-Alder suggests, you'll need a dual-display dock. Avoid the $50-100 docks on Amazon that claim to be dual- or triple-displays, when you read the fine print you'll see that they really only support one display (you can connect 2-3, but they all show the same thing).

Dual display docks that work well with Macs include Brydge (Stone Pro), Elgato, OWC, Belkin and Kensington. Personally, I have used an Elgato dock, and just yesterday I ordered a Brydge Stone Pro – I like the aesthetics, Brydge makes great stuff, and through Nov 8 the dock is $50 off, making it the only sub-$200 option for now.

https://www.brydge.com/products/stone-pro

Best results will be with DisplayPort connections. To use two of that model display, you would need a Hub that also accepts USB- C charge cable.

You can't even consider daisy-chaining monitors unless one (or more) has an input and an output for the exact same interface you are using -- and NO you cannot expect the display to do any conversions for you.

what Make&model displays?