When it comes to finding synonyms for "go at it", it can be tricky to accurately convey the same level of intensity and enthusiasm that the phrase often implies. However, some options to consider could include "engage in", "participate in vigorously", "dig in", "throw oneself into", "embrace fully", or "attack with gusto". It all depends on the context of the situation and what specific connotation you're trying to convey. Whether it's referring to a physical activity, a heated argument, or tackling a challenging task, there are various ways to express the idea of diving in headfirst and giving it your all.