How do I face an unseen translation without a dictionary?

First thing: don't panic! I know it is scary, when you are in front of an long unseen translation and you don't seem to recognise any word. What you need to do is take a deep breath and start unravelling the text. Divide the whole text and work with one sentence at a time. Once you have your sentence, underline the verbs. If there is more than one verb then you will see if there is also a conjunction (e.g. ut, cum, qui) introoducing a subordinate clause. Ignore that clause and focus your attention on the main verb instead. See if the verb has a plural or singular form and on that base find your subject in the nominative. You wil find then that the other bits are not so dfficult to put together as long as you are able to recognise their case. Having done so, get back to your subordinate clause (you need to know your sintax here!) and translate it, always asking yourself if the verb requires a singular or plural subject. Keep doing this sentence after sentece until you get to the end of the unseen! If you don't know the meaning of the words, again don't panic! Try to relate it to English words (or other European languages you may know) you know. Most English words derive from Latin and you will be surprised to see how much you actually already know!