Kaliningrad is placed conveniently when one comes from western Europe.
It is near but in atmosphere it is very different and interesting due to the Russians. Still it requires an open mind. Learn a few Russian words and you are welcome most places but avoid dark places at night - as everywhre in the world.
It is possible to by by with English or German. The museums and churches are interesting but the best is the beaches especially Kurskaja Kosa with a National park near Zelenogradsk. It is a must if one likes nature. It is easy and cheap to go by bus from the bus terminal (voksal) to Zelenogradsk where there is a helpful touristservice. Find the adress on the internet.