How the hell does immigration work.

So to start im 19 my partners 18, im a uk citizen he is from the EU, weve been together for almost 3 years now but as hes finishing his studys right now we are long distance. He proposed to me on Christmas eve and i said yes, we are looking for him to move to the uk.

He wants to find work as an engineer but we honestly dont know what we are doing. We want to move in together, both be able to work and live happily, but it seems rlly far off with how little we know. Im not sure if we are supposed to apply for a family visa, work visa or what, its just very confusing.

Any advice on how to go about this process is really appreciated, thank you