Every Oleh, regardless of age, is entitled to two pieces of luggage with a maximum weight of 50 pounds each and up to 62” (height+length+width). Olim will be charged for additional, overweight or oversized luggage, just as any passenger. Do not expect the airlines to be lenient.
Pack all of your original documents in your carry on bag. You will need them for processing at Ben Gurion airport in Tel Aviv. You will not be reunited with your luggage until you have completed your Aliyah processing. (Additionally, it is generally good practice to keep valuable items in your carry-on rather than in checked baggage).