Esp8266 wemos mini d1 trying to build the tiny word clock by espruino

Hi - there's already a driver for MAX7219, so it should be pretty much copy & paste: http://www.espruino.com/MAX7219#graphics-library

Just use software SPI if you're beginning so you don't have to care about the pins used:

var spi = new SPI();
spi.setup({mosi:B15, sck:B13});  //<-------------- change to the p;in names you use here
var disp = require("MAX7219").connect(spi, B14); //<------- and here

var g = Graphics.createArrayBuffer(8,8,1); // Create graphics
g.flip = function() { disp.raw(g.buffer); }; // To send to the display

g.drawString("Hi");
g.flip(); // update what's on the display

The MAX7219 actually does the scanning itself, so in this case I don't believe flicker will be a problem for you