Global Scale Modeller

Hi all,
I'm going to have a go at weathering for the first time (on a tank) but am a little bit puzzled about one thing.
I have printed the model and put on the base coat (olive drab) and am going to use some ready made enamel washes to add streaks etc, the reason I'm using ready made before I'm shotdown for not making my own, is that I'm colour-blind and would not be able to mix colours very successfully.
Anyway the base colour is acrylic based, so I gather that I should protect this with a varnish coat (Matt or gloss?)but what medium should I use for this acrylic or enamel? If I use acrylic will it not be attacked by the wash and if so what's the point of applying it or use enamel which again would attack the acrylic base coat or are people using Future floor polish for this purpose.
Despite watching numerous YouTube videos I've not found an answer.
Thanks in advance, Mark

I too was a bit unsure having only returned to the hobby earlier this year. with the vary same questions.

The advice I was given and read was; undercoat, chipping coat (if you want any),base colour, cam, then chip, gloss coat, decals, matt coat weathering.

Not saying that's correct or the only way just what I was advised as a starting point.

alcad aqua gloss (24hrs to dry) or Tamiya x-22 clear mixed 50/50 with Mr Hobby self leveling thinner ( dries much faster).
For a matte finish later in the build I use Windsor and Newton matte varnish ( acrylic mediums) mixed 50/50 with Ultimate thinner

Thanks for the advice.

Hobby enamel paints should not attack properly sprayed and dried acrylic paint. The main reason to apply an acrylic gloss is if you have applied decals or weather affects that might be disturbed by the wash or where you need a gloss surface for the weathering technique. When applying a wash you want it to spread through capillary action. A matt surface won't allow you to achieve the same effect.