Depends on what you want to practice.
For a total beginner, Those plastic balls are OK for learning to make contact with the ball, but beyond that absolutely useless.
Appreciate that you want to do this on the cheap but tbh golf isn’t the cheapest of activities in the first place. 3 quid for a bucket of balls at the range is the least of your issues. If you don’t want to pay that see if there is a golf club near you with a practice area. It’ll be for members only but noone will know you aren’t one as long as you rock up looking like they do. Other than the club pro, so wait till his shop has shut. You’ll need a bucket of balls to practice with obviously.
As someone who got down to a very reasonable handicap back in the day.. If just starting out here is my advice..
Learn the fundamentals before you even try hitting a ball. If you aren’t paying for lessons then learn the proper golf stance at least. Correct position before you swing the club is the most important part of the swing.. Get it wrong and you will always struggle.
Practice with no more than a 7 iron…
If you want to play on a course then the old saying ‘drive for show, putt for doe’ is very true. If you intend to take up the game spend as much time chipping and putting as slogging endless shots down the range.