how do you teleport to a place where it is blocked to newcomers on second life?

The blocking of parcels or regions can be done for many number of reasons, and without you being more specific as to the place you're trying to get to, it's hard to give an exact answer.

Let's start with the most obvious. It could be a privately owned parcel or region. In other words, someone has paid money (in the case of an entire region, a lot of money) to have a private space for themselves and their friends. Some real world companies buy regions as training areas or virtual conference centers for their businesses. The only people allowed in are people the owners allow access to. Unless you are friends with the owners or work with the company, you can never go to those areas.

Some places have suffered attacks from griefers in the past. A griefer is someone who purposely disrupts Second Life, either by using certain objects or weapons to target individuals, or use certain tools to make a region overload and crash. As many serial griefers are eventually tracked down and banned from SL, they have taken to creating new avatars on fake accounts - sometimes several avatars a day. Because the griefers know their avatars will be banned from SL - probably within hours of being created - they don't have payment information added to them. If the area has suffered constant griefer attacks, the owners make it so that the region is closed to all avatars who do not have payment info on file.

This can be rectified on your part by going to your account page at the Second Life site and adding your credit card details. This is NOT premium membership and you never have to use your card to buy in-world money if you don't want to.

For ever one newcomer with a genuine sense of wonder and a desire to become an integrated part of the SL community, there are at least 10 who who don't and go around begging for money or jobs or just asking the most stupid questions and generally annoying the heck out of older residents. Others simply walk into someone's private home and try to live there and won't leave. Some become abusive when asked to be more respectful. Yet others - having heard the stories that SL is all about 'free cybersex' - go around naked and bug people for sex. In most cases, these people either get fed up and leave or they learn the ettequette of SL and settle in to things. 30 days is around the time needed for this, so some owners put a lock on their areas that require a person to have been in SL for at least 30 days before they can enter their land.

Some places belong to groups with a specific interest, such as a college with an extended SL campus, or a themed role-playing group. Other examples may be areas only for a specific religious group or for gay people only. In such cases, you may need to be a member of that group, or have to undergo an interview or trial process before you can go there.

Some areas of an extremely adult or pornagraphic nature require you to have age verification before you can enter there.

Finally, if you have done something to annoy an owner of an area, they can add you to a ban list to prevent you going there. If you think this is a mistake, you need to contact the owner if at all possible.