I'm curious as to exactly what you mean by "transition without transitioning." Transition is composed of different elements for different people, and not everybody cares about the same things. In the end, the primary goal is to make your life better, and there's no single recipe for how to do that.
When you say "transition without transitioning"... do you mean no surgery? No hormones? No name change? No hair removal? No women's clothing? No femme clothing (not quite the same thing)? No voice training?
I don't like to give pat answers to difficult questions, but I can't really avoid it here: the simple answer to how to transition while avoiding some particular aspect of transition that you don't think is going to make your life better is... to not do that thing.
Now there's a completely different question here, too, of course—and important question, but a separate one: how are you going to get other people to go along with you?
That's not something anyone can help you with without knowing more about your personal circumstances. Maybe, JUST AS AN EXAMPLE, you want HRT and you live in a place where healthcare providers are suspicious of nonbinary trans people or trans people who don't want surgery or trans people attempting a "boy mode transition" or butch trans women or any other subset of people whose lives would be surely made better by HRT but who don't fit whatever stereotype. Narrow minded healthcare providers have been a recurring problem for trans people for decades and there's TONS of folks here who can help you deal with them. But that's going to require more specific questions.