It is essential that you fully assess any data before you start. It is your responsibility as an analyst to satisfy yourself as to the legitimacy of the analyses you intend to conduct resisting the temptation to just "plug and play" particularly when using an international dataset that is already established.
Remember that you are unlikely to be the first analyst using this dataset so a useful first step should always be to look for analyses already published from the source. For surveys such as the European Social Survey or the World Values Survey you will find a list of publications on their website.
Looking at existing analyses will provide you with important clues as to what you need to take into account in analysing that particular dataset, such as population coverage issues or which weights if any need to be applied .
In particular, look for analyses that are on a similar topic or that use similar types of variables, continuous, ordinal, nominal, etc. Reading existing publications will also provide you with information on how you might display the data in tables and graphs. It is very rare that you will be conducting unique analyses so make use of what is already available to improve your analysis but obviously with a questioning mind.
