Question: I am very new to indoor rock climbing, I want to climb barefoot, I heard some people advise against it,  

Anybody here has any experience or can give any suggestions on barefoot indoor rock climbing?

Answer: 
You definitely **can** do it, and it is fine where you have clean, dry climbing surfaces. I have had no problems doing it on occasion in the summer when I have not had my rock boots, but I wouldn't want to do it.

I don't know how practical it is to train this way though, as if you decide to climb outdoors it will not be as useful as having learnt the skills with proper rock boots.

Rock boots require a slightly different technique, but are much grippier and you remove the risk of catching a toe on something!
its way easier in the gym to go bare foot. Shoes just make you unaware of how your body should move. Especially roofs it is easier and the big to can toe hook a lot of holds your shoes cant. High feet that require the foot to claw are way easier bare foot. I would say 80 percent of climbs are easier bare foot and the other twenty are better with one shoe and one bare foot. The same is true for outdoor climbing. shoes have made peoples feet weak and they have lost touch with what there feet can do on climbs.