Welcome to the 'tank!
The necessity of fertilizers really depends on a few things. If you are just beginning with live plants and would like to try out a few, then I would say you could wait on fertilizers and rely on water changes instead. If you want to plant a lot of plants, then you will probably need to supplement them with a fertilizer.
There are many variables involved that make it difficult to give you a straight answer. Could you describe your plans a little further such as how many plants and what kind, the tank you will put them into, and the amount of light you will be using? This will help.