Second question: Is a water cooler nessary? My cpu never gets hotter than 58C On the stock cooler so do I need a better cooler?
More aboutquestions overclocking
There's no certain number we can give you, it'll go as high as it can but I would think a 1200 should get to at least 3.6 on the stock Wraith cooler. No watercooling is required, especially on that chip.
Goto youtube and type in ryzen 3 1200 + your motherboard for guides and suggestion.