Is a vibrator unsafe...?

to use more than once in a day? im 20 and i "please" myself almost every night. i have never used a vibrator before, cause i'm kinda nervous about using it, on account of me never sticking anything in my before. Sometimes i'll do it twice a day. Also, do you have any suggestions or techniques that i can use a vibrator with? and which is better, a vibrator or ?