Personally, I think you got lucky lol.
Didnt measure you starting SG, and used baker's yeast? Someone's watchin out for you! No mention of yeast nutrients, but the mangoes probably brought something to the table.
Any idea how much fruit you used? Bernard can guesstimate your starting SG, so we can ballpark your ABV and atleast find out if you're safe for storage or not (10% ABV + usually) Without knowing your Starting SG, you cant calculate your ABV.
A common formula for ABV calculation:
Starting SG - Finished SG / .735 = .####
.#### = ##.## %
An Example:
1.085 - 1 = 0.085
0.085 / .735 = .115646
= 11.56 % ABV
Instructions on the basics of an F-pack can be
found here but this is done towards the end of the process, after the wine has been stabilized with k-meta + sorbate. If you havent added potassium sorbate yet, adding more sugar just makes more alcohol. Sorbate keeps the yeast from continuing to reproduce and feed on this sugar.. So you can sweeten the wine because the yeast wont consume it.
I would chalk this up as a learning experience and an understanding that you got lucky lol. Were I you, I'd make sure I knew how to work the hydrometer, adjust the reading from temperature differences.. Then pick up a Titritable Acidity kit, for like 10 bucks at the local brew shop, and learn how to take TA (acidity) measurements.
If you can get testing those two aspects down, then you can begin to understand the concept of Balance. To achieve a finished wine that is fruity, and not so dry, you have to find the balance between the alcohol level, the acidity level, the amount of fruit used, and the amount of residual sugar/sweetness in the end.
If the alcohol level is too high, it hides the fruit; if the acidity level is too high or too low, it will make the wine seem muted or dull; if you dont use enough fruit then there's no flavor to bring forth; a certain amount (changes with the type of wine) of sweetness usually helps to bring out hidden flavors within the wine but too sweet and you cant drink much without a stomach ache while not enough sugar keeps those flavors (generally the fruity ones) hidden from out palette.
When you achieve the right balance, you'll have a wine that has the flavor of the fruit you used, enough alcohol to keep it from spoiling, and enough acidity and sweetness to flesh out that flavor.
Let me know if I can be of more help