I'd recommend this subreddit(SoccerBetting) over a prediction site that might sell you their paid picks.

On that subreddit, you'll always find some bettors sharing their free predictions through the daily threads, and if you're lucky you could even catch bettors on a heater sharing consistent winners.

One thing to note is that the predictions you can find there won't always be reliable, but it's better than buying picks if that's your plan.