Many clubs will lend you equipment when you are doing a beginner course, they generally then like you to start purchasing your own so that their kit can be used for new beginners.
There are two options as a beginner, the first is to buy individual items one at a time until you have a full set and the second solution is to buy a starter.
If you are buying without trying equipment on make sure that you have your measurements e.g. chest measurement for jackets, waist measurement for breeches etc…