Since you will come across (see/find) them anywhere, especially when you start learning them and focusing on them, you will need a way of recording them for future study, review and use. This means some form of a vocabulary booklet, which holds your new words you deem important.
There are 2 main ways to organize your vocabulary: alphabetically, or per topic. Neither is better than the other, it is just more appealing for students to use one or the other.
Here you just take a little booklet and every few pages (3 to 4 pages) you have a new letter of the alphabet. That way you can easily find what you are looking for.
Like the course, you pick a booklet and every few pages (3 to 4 pages) has a different topic: food, holiday, work, school,… That way you have all important words related to one topic all together.
Every time you will need to record at least 3 things: