well...
Malt is the malted grain (usually barley), still in "grain format", i.e. it looks like something that has been growing

Usually called "whole grain brewing" or similar.
When you buy malt you buy it whole or crushed, but it needs to be crushed before mashing.
Malt extract comes either in powerd or liquid form, hopped or not hopped.
Usually called "extract brewing".
When using malt extract there is no need for mashing, you will need less equipment and you will use less time in brewing.
What you got sounds like hopped liquid malt extract then.
I'd stay away from using sugar, since it gives alcohol but not taste or body. I'd put in one more can of malt extract instead, or a bit of non-hopped malt extract.
It will work with sugar as well, but it will be better/higher quality with bigger malt base.
Be careful not to pitch your yeast while the temperature is too high, it will die at around 35-38 degrees C.
I usually pitch my ales around 20 degrees C.
But I think the best way to do this is that you follow the instructions and see how it turns out.
If you're not satisfied with the outcome, I can give you advice on how to improve in some steps.
If you are satisfied, congrats, you have a very easy and quite cheap way of making beer
And cleanliness is the most important thing to remember
