Here are some suggestions for accomodation in Germersheim, all within a maximum of 10 minutes walking distance to the conference site:
Germersheim is a small town and thus does not have large capacities for overnight stays. In case you cannot make an arrangement in Germersheim itself, safest is to go with a place in Lingenfeld, the neighbouring village, or in Speyer, a popular tourist destination. Lingenfeld is within 5 minutes and Speyer 15 minutes by train to Germersheim. Trains run every 30 minutes. Each train ride will be about 4€.