i'm thingking of getting a BTS soon. i like it, and also it comes from my country, making it cheap and easily adapting to our circumstances and climate here.

anyone knows their best care?

i'm planning to make him a 42 gallon tank (80x40cm) will that be enough?

and do they shed?
any signs or how long is the shed?

how many times per week should i feed it? someone told me his BTS eats 3 times a week, is that enough? or i should feed it everyday?
i'm also googling it, but knows somewhere here have more experience about them, thank you..

That tank is nowhere near big enough, you need 120cm x 45cm at the very least. Yes they do shed, it changes rate as they grow. Check Blue Tongue Skinks - Welcome to BlueTongueSkinks.NET ! for more info

it's a juvi, i'm getting a 90x33, i can't find anything bigger than that, perhaps i'll nake one myself when she grows..
thanks

The depth is going to be too little when it gets to around a foot long. I dont know what you can get in your country but a front opening vivarium made of wood or plastic would be best.

in order to have that, i have to make one myself, or in the wod craft, but i'm not sure, should i give it some rubber/glue so when there are heat lamps on it it won't crash? (glass expand when it gets hot)
i'm trying to make that for my leo first, based on what i see here BTS tanks are never that big. but i know BTS here are quite unhappy lol.
80.40 is bigger than 90.33 right??

So long as the lamps arent directly heating the glass you should be fine, glass will easily withstand the ambient temps needed.
80x40 is slightly bigger yes, it gives a surface area of 3200cm2 but for an adult you really want to be looking at 5400cm2 as a minimum to keep the skink nice and healthy, ideally 7200cm2 or bigger.

wew that big?? i can't find anyone as big as that, and i don't think i have the room \they said here it is really ok, better than ok even!

Here we use 120cmx60cmx60cm for our blue tongues. Im aware of different views but i couldnt bring myself to reccomend putting a 60cm lizard in anything less than that.