Hi, first of all I advice to boost your paint set with vallejo paints, if you're just beginning. They're cheaper, last more and can be identical in results. There's one exception though - for the base metal colour of the hallowed knights you'd better get the
gw leadbelcher pot as vallejo metal paints tend to be a bit more watered down and are not that easy to work with for applying the base layer(you need a flat brush and a more solid paint to quickly spread it thinly around the model).
You've probably seen this one -
https://www.youtube.com/watch?v=bK3Z1cbjEkY
An important part in following
gw tutorial videos is working out which paints you can do without as sometimes they're adding very small and generally not needed
imo effects (which ofcourse require a different shade and pigment paint pot...).
For example, in the above video, you can either forego the edge highlighting with stormhost silver or the layering with ironbreaker. The first choice will result in almost identical results as silver highlighting on an already light silver surface is hard to spot. The second will result in a darker metal with its edges brought forward by the line highlight.
Here's a handy chart for choosing paint analogues
https://www.dakkadakka.com/wiki/en/Paint_Range_Compatibility_Chart