I agree with everything written in the previous posts.
You do not have to worry, masturbation is safe and healthy, and if you start to explore your sexuality, feelings, reactions etc, I think you will soon now what exactly is the best for you.
The only risks of masturbation are connected with cases when people insert into their bodies different things which are not very clean, then it can cause infections, but I am sure that this is not your case.
Just follow your feelings and enjoy all kinds of stimulations which are pleasurable for you.
the hymen can break from everyday things and it isnt really a very reliable way of telling if a woman is a virgin or not. things from using tampons to riding a horse can cause it to break.
but if you do not want to risk it then the best way to to break it is to not penatrate into the vagina but to rub the outside and your clitorus. that is a very effective way of maturbating. or inserting your finger only a small distance into your vagina. personally i prefer rubbing the outside of my vagina and clitorus compared to inserting a finger or two.
as for the duration to have an orgasm, it is completely different for all women. it may take a long time, half an hour or more, or a matter of minutes, and yes some women cant and dont have them.
no it will not make your vagina loose. you can insert one or two fingers into your vagina and it will not make the slightest difference to the tightness of our vagina.
Safest way...well it causes no damage
Hymen can break for 100's of different reasons
No time frame to have an orgasm...some women can't even have them
Make it loose...no.