Buy a potty and a toilet bowl cover
The easiest potty which you will find on the market, without music boxes and unnecessary gadgets. Although it may depend on the child. My son would treat such a potty playing as a toy. We bought a potty for the boys, in the front it is a bit higher so that the pee does not stick out and it does not run on the floor. My child got it straight away, what it is for and never saw it, to use the potty for other purposes.
The simplest shell cover. buy, buy ... because the potty may not be effective. How the child will insist, that she wants to pee just like Mom or Dad, this overlay will save your ass 
ROTHO potty
This potty may not be the cheapest , because in the market you can buy for PLN 12, but be careful, that it is worth the money! In addition, we have many colors to choose from and you will certainly choose a topper, which will blend in with the style of the bathroom :):)
Rags, tetra, foil bags, gloves
get ready, that you will have to wipe huge puddles, collect stools from the floor, wash wet clothes, wash the kid in the shower. And when you get over it, you will see another puddle ...
I recommend tetras diapers! You throw one like this on a puddle of pee and it soaks in a moment, and you only need to dry the floor.
Plastic bags they will be useful for poop. You can pack them and throw them into the garbage can, same as you did with dirty diapers. But you can also grab the pile with gloves and take it to the toilet bowl - your child will like it, but be careful not to let it repeat itself!
Don't let it the child to climb on the sofas, chairs and other furniture with upholstery - washing and drying the furniture after urine and faeces, on a cloudy cold day, it's the worst that can await you.
Prize
Want reward? Choose something your child doesn't know yet. Maybe chewing gum (mamba), maybe TicTac, maybe a handful of raisins, or just a kiss and applause ?
Idea, which will be the best reward for your child, when he has achieved his little success. Tell him about it. Explain, that when I pee or poop in the potty, this will get a reward - show it and put it high on the shelf. So that he can see and remember, that he will get an award if he meets a certain condition.
Diapers
Perhaps I will worry you, but this is not the end of the Pampers expenses. Even if your child masters potty pissing, it's during a nap, and even more so at night he will do a diaper. This process can take quite a long time.
Going for a walk without a diaper is another difficult school. Better to wear waterproof panties at first, because if you do, you will fall into the whirl of backyard fun, it will surely forget about the potty, especially, that he is not in sight. There will be no potty, what he will do? Will do in panties.
Towels, old blanket and what else?
Collapse all carpets, bury the most valuable items, who don't like water, moisture and absorb odors.
The child will want to play on the floor - put the old one koc or towel. Let him not sit on the cold floor.
You have to develop yourself Action plan. Think about all possible situations, that may happen to you in connection with potty training. Maybe you're worried about stuffed animals? Or decorative pillows on the sofa? Bury it, Save yourself the stress of a possible loss - not everything can be washed, and even if you get rid of the stains, it will remain no pleasant smell.
Educational book
Consider getting a potty book. It worked for us.
"Potty over the potty" by Alena Frankel
Available for purchase at Empik bookstores, Merlin and many more. The booklet comes in two versions:
Change into an Angel
Not allowed You scream, complain, be intrusive and malicious.
"Oh dear you did(you) Pee", "Dear look you have wet panties", “We'll go pee in the toilet together?” – you must be cute, nice and loved.
Do not speak, that poop is hideous, smelly and in general.. it's an embarrassing and strange experience for a child anyway.
remember to agree with your child's other caregivers, rules of conduct in the coming weeks: when we put the diaper on (for a nap, a walk, e.t.c.). How we praise, how do we translate, what we use nomenclature (a-a, cup, kupka, Pee, side, other) and so on.