In the New Testament all believers, Jews or Gentiles, are called priests:
1Peter 2:5 you also, as living stones, are being built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ.
1Peter 2:9 But you are a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of darkness into His marvelous light;
Revelation 1:6 and has made us kings and priests to His God and Father, to Him be glory and dominion forever and ever. Amen.
The New Testament does not mention a priestly class of believers in contrast to the laity.
There is no reference to the Apostles in the OLD Testament. The Old Testmant is full of prophets, priests, and kings. The New Testament had the twelve apostles, the followers of Jesus Christ.
Some famous priests of the old testament were Aaron and Eli.
According to biblical teachings, believers in Jesus Christ are considered priests in the order of Melchizedek. This concept is discussed in the book of Hebrews in the New Testament.
In the Old Testament, priests were the ones who could offer sacrifices.
Exodus 39 is where you can find the answer
Something that is called in the old testament "shemen hamishha" which in translation to English means "anointing oil". the oil has specific ingredients that is mentioned in the old testament.
Priests Prophets Kings
ephod
I believe 30 year old
No, they were one family from the tribe of the Levites.
New Testament
Yes, the Old Testament priests were members of the tribe of Levi. The Levites were chosen by God to serve as priests and carry out religious duties for the Israelites in the tabernacle and later in the temple.