Im buying this house and it needs a lot of work and the frist thing that has to be done is the bathroom that my son would use. it has mold everywhere my husband and I are going to do it I just dont know what else to do with it.

First, some basic questions:

Has this house been vacant for some time, allowing mold to build up? What kind of walls are in it? (I assume the side on the left is a wall). What is the area on the inside of the tub/shower like? Is it just as moldy?

Is there any indication of a leakage? Is there a ventilation fan? A window?

I think the remediation steps to be taken would depend on why the mold is there in the first place and what moisture issues might exist, beyond those that commonly occur in bathrooms. I also assume that this is the only room in the house with a mold problem?

I assume you plan to wear respiratory protection when you work in this room?

Im not sure how long it has been vacant but I do know that the people that owned it befor had started to work on the house but ran out of money and had to forclose on the house and the walls are plaster wall the tub/shower walls are in the pic at the end of the post yes there is a ventilation fan but it dose not work and no window no indication of any leakage so thats good and yes that is the only room with the problem there is another bathroom in the house and that one is fine all it needs is some updating and the ventilation fan has to be fix cause it dose not work

Just the facts that it is a bathroom and there is no operating fan can give you the cause of the mold.

Treatment is killing the mold that is there and fixing (and using ) the vent fan. It's possible that you have mold growing inside the walls but is is just as likely that all the mold is where you can see it. You may want to consider removing the shower surround so it can be cleaned completely behind it (plus, there is no way to get all the mold out of all the nooks and crannies of that surround trim).

How far you need to go beyond cleaning depends entirely on how far the mold has gone.

I know we are going to gut it the only thing that will be reused is the tub but everything else has to go!!!!!!!

Then I would reevaluate it after all the demo is done. This will give you the best information as to how far the mold has gone and what you have to do to make it go away for good.

ok thanks i will give updates when the demo's done but more help is always welcome

Make sure you have your ducks in a row when it comes time to start gutting that old bathroom.
Thinks like if the tub is starting to rust, is chipped or starting to feel rough from all the years of scrubbing need to be concider it it's time to replace it or at least having a pro come in and refinish it. (no not some DIY paint job that's not going to hold up.)
It's always suggested to replace (no not just rebuild it) the water valve while the walls opened up, if it's old galvinized drain and supply lines get rid of them to and replace with PVC drains and Pex or copper water lines.
Galvinized plumbing will always leak and close up on the inside every time.
Instead of one of those cheap stick on enclosures, use a nail on one instead. It gets installed directly to the studs no wall board behind it.
It will be at least three times as thick as what's on there now.
Anytime I see a stick on encloser I just assume there's going to be wall damage behind it and someone was trying to cover something up instead of fixing it.

I would say it's a total gut job, replace it all. you can get a junk tub for $100 if you run out of money.

but DIY makes it possible to upgrade. you can do ceramic tile surround on the tub for double the materials price of a 3-piece surround. for what it costs to have a plumber drop in a new tub, you can drop in a whirlpool tub. that's a tight space, maybe a pedestal sink instead of a vanity and top... about the same price.

oh, and a new fan in the ceiling