English-English dictionaries and thesauruses should be in daily use when writing in English. In addition to accurate definitions, they also provide example sentences, information on patterns of use, and list synonyms/antonyms. Do not rely on a bilingual dictionary (or google translate!). If you use a bilingual dictionary, make sure that you confirm the meaning and use of the word in an English-English dictionary.
There are many referencing styles and accurate referencing requires the use of style guides - no one can remember all the details of all referencing styles. As the referencing style is usually dictated from the outside (by your professor, by the journal), you need to be ready to use different styles. Thus, using the style guide is an essential skill. Referencing tools are useful but not perfect and might require some tweaking before they work accurately. On the ELEC-C9801 course you are given a choice between IEEE or APA, so I've added resources related to these two below.