Civil engineering the oldest known engineering of the world. And hence it is related to everything. The question you have asked has different views from different people. Here I have listed career options as per different interests.
Career for those who want to work in the core construction area
You can go for Designing (Structural design)
You can join different consultants such as Geotechnical consultants, quality control consultant, etc.
You can also find the above domains in big construction companies itself.
You can choose specific roles where you are good at such as surveying
Career for those who want to build their career in Roads and Highways
You can join a company which is into road construction
You can go to traffic engineering
Career for those who want to build their career in environmental engineering
You can join a company for water treatment
You can go for wastewater treatment
You can also go for fecal sludge management
Career for those who want to build their career in research
You can do an M.Tech21 and then Ph.D. from a reputed college, where you can do research for new materials, methods and much more, Most of the people interested in this work as a faculty member in a college and simultaneously do research works.
Career for those who want to build their career in Construction Management
You can be a planning engineer, site execution engineer, etc if you do a construction management course or have some experience in the construction site.
You can also go for Building Information Modelling (BIM)
Note all the above roles I have mentioned are assuming you are a fresher. once you gain some experience you can choose a more specific domain such as tunneling, high rise structure, roads and highways, bridges, metros, Sewer treatment plant work as a more responsible domain like project engineer or construction manager and project manager.
As you grow you will learn more and you will find your interest more clear and you will go there.
Some more options for civil engineers
Facility Management
Operations Management
Contract Management
Some options for Civil Engineers other than the construction industry
Software development for civil construction companies there are companies like, CSI, Bentley, Autodesk which does that.