Do Pentecostals include the Old Testament in their Bible? Or do they only follow the New Testament? I have a church near my home, and it's called the New Testament church. So, just wondering if their Bible doesn't have the Old Testament.
As per my previous comment, to the best of my knowledge, all Pentecostal denominations use the regular Protestant canon which includes the 39 books that are frequently thought of as the Old Testament. This excludes the 7 Deuterocanonical books that are included in the Catholic and Orthodox canons. 

The term "New Testament Church" is fairly common parlance amongst Pentecostals (but by no means restricted to just them - eg), so it's not particularly suprising that a particular congregation may be named as such. It's not any kind of statement against "following the Old Testament" as such, but it's more based on:


The people of God in the Old Testament are not usually referred to as "the Church", but rather as Israel.
It's a subtle acknowledgement of the belief that many modern churches have adopted beliefs, traditions and practices that do not have a biblical basis and have thus departed from the Church found in the New Testament which is believed to be what we should be aiming to return to as our model.