Definitely do a placement if you can! Even if you are in a department that you don't enjoy, you will still gain so much from it, and it will help you recognise what engineering you do and don't enjoy, which will help you choose elective modules later in university. It is also a fantastic opportunities to meet people and gain confidence and respect within the professional engineering field. Wherever you go, make sure you build your network and chat to everyone. I met a safety engineer on a course by coincidence and through that contact I gained a 3-month summer role in safety engineering that then allowed me to get my perfect graduate scheme in nuclear safety. The company you work for has invested time and money in you so want to retain you as an engineer when you graduate, don't be afraid to ask for what you want and push for it!