Thats very very good for a first mini, my first mini was a space marine, and he was solid red with a black gun and black eyes!
I was pretty young at the time.
Youve got good brush control as your mini looks ok close up, but I want to say your over complicating things, especially since your new.
Id say pick two tones of green, one for armor one for cloth parts (a little brighter than youd want on your finished model) then use the GW inks to bring out the detail. The new GW inks are fantastic, they dry Matte and are worth every penny, they do darken your model a little bit so basecoat with a light color. You can follow the ink up with a drybrush of lighter greens. Then pick out some panels here and there with your complementing colors.
Basecoat-wash-drybrush is the classic technique for making a color pop on an individual model, and after like 4 years of messing with advanced techniques like layering, blendinging, and feathering, I returned to the old wash and highlight to for painting units of models.
Another thing. Your ideas of using the bright greens to create the effect of light or glow coming from the armor... Good idea, but lighting effects with paint is something you do NOT want to try to wrap your head around. Ive been painting for 8 years and I still stay away from it! Its crazyness!!!
Here are two clan mechs painted up with the good ol base-wash-highlight routine, using all GW paints. Picked out a couple panels and did the cockpits, all done! Easy and effective, and good for making sure all your troops are the same shade.

You can see all the detail, they look nice on the table, and they took me very little time to paint. Its ALL about the inks!!!!!
Also yeah GW tools are overpriced, however I tend to use GW and Vallejo paints. Both are pricey, but I prefer them.
Whatever the case use water to thin your paints to a milk like consitency!
Also basing, its worth the extra effort. Glue sand down (I do before priming) paint and highlight, then invest in a tub of static grass. Its like $8 but itll last you multiple armies.