sorry for the late response...
Well, it depends on who you have to play with and where you want to go in the end. Is magic something you want to play for fun or competitively, primarily speaking? Do you have any friends to play with you or just local people?
The answer to those questions makes defines how meta and how expensive the decks you shoudl pratice with should be.
A good option regardless, however, is if you have a PC, downloading the steam game "magic duels". It´s a free game that gives you some starter pack collections you can make a deck from and then you have quests that give you gold every day with which you can buy more packs. All totally free of any expenses, thus allowing you to get familiar with the game without going over your budget while still learning.