Good that you posted here.

I would suggest doing more homework first before continuing on Just poking yourself with what the internet says is ok..

As for what doses, this depends in few things.
Most that understand reta somewhat now are wanting to start low dose and work up like

.5mg 2 x per week every 3.5days..
After 2nd week go to 1mg 2 x per week
Hold here until 3or4th week see how your reacting to it.

After all if you injection a high dose and it's too much, nothing you can do but wait until it leaves your body.

yes your math is correct if you got a box of 10 vials for each. but the amount kf bac water depends on personal preference, and you want to make it easy for yourself. like if its 10mg a vial and you put it 1cc of water, then every .1 on the pin is 1mg. depending on how you plan on dosing it you might want to add different amount of bac water. and also if you dont know, when you add the water the vials are usually vacuumed so its gonna draw the water out of the pin automatically and you dont want to shoot the water directly into the powder block at the bottom, you want to let the water out of the needle slowly(manually) and aim it towards the side wall of the vial so it slowly trickles down the side instead of letting it shoot directly into the powder block because it can destroy the compound inside the vial if you shoot it directly onto the powder. so make sure you hold the plunger as you are sticking the needle into the vial and slowly let the water out yourself otherwise the vial might suck the water straight out of the needle on its own and ruin your shit. alot of those peptide vials are vacuumed shut, sometimes not tho.