There isn't a place where you can find a general overview of neologisms in Gothic. Although there is no general list, there are certain neologisms which are used in different places and can therefore be defined as neologisms which are accepted. Here are some examples:

garahnja (male an-stem) - computer
fairrarodjands (male nd-stem) - telephone
kaummunismus (male u-stem) - communism

maþl (neutral a-stem) - (online internet) forum

Some of these words are completely new made-up words, like garahnja or kaummunismus, but other words like maþl already exist, but have an added meaning which can be applied to this time. Another example is saliþwa, which ment a lodging or guest room, but can be used for the modern word 'hotel', as this word has about the same meaning.