In general the safety in the workouts depends on how good the form is and how fast the weight is incremented.
When the weight is small, the form does not matter, so in the beginning a lack of a good understanding of the proper form does not show up. But as the weights increase more and more, the form factor becomes more and more important.
Learning the form is not trivial, but there are good videos in youtube to show the good form. But I like the videos in "Starting Strength" startingstrength.com/
. These videos are mostly educational, not for impressing others. Everything is being explained in great detail. That is wonderful I think.