If Tryingtojoin is definitely headed for a CER and wondered what kinds of tasks and/or specialization they have, I will defer to a Sapper (but I generally concur that it is construction engineer, combat engineer, and combat diver).
Tryingtojoin‘s question re engineering specialization raises the question of academic specialization and availability of non-Combat Engineering occupations. Academic specialization can be either with respect to which classifications employ which kinds of engineers, or to actual performance of specialized engineering tasks.
If clearing mindfields and building/destroying bridges is not the kind of engineering Tryingtojoin has in mind, but mud, muck and everything green is somehow preferable to clean sheets, there are other options, particularly if Tryingtojoin is interested in being an officer. Sigs officers are in fact "CELE (Land)". Maintenance officers are "EME". The last "E" on each of those is "Engineer". NCM occupations mirroring those classifications are less engineering and more technician but address the same issue.
If the question is one of academics -- different engineering degrees can lead to different classifications. Combat Engineers tend to have more civil engineers among their ranks; Sigs like electrical engineers; EME likes electrical engineers and mechanical engineers. Chemical engineers, engineering management types, etc. have all found homes in the army. Nautical engineers and aeronautical engineers might find better homes elsewhere
As for specialization within an engineering discipline, this is much rarer - chemical engineers working in NDHQ on fuels or biowarfare are good examples. Not many of them!
All of which is moot if you‘re a combat engineer, but I couldn‘t resist reminding the Engineers that they aren‘t the only engineers in the Army.