I think before buying them you should have done your research on bitcoin wallets.
Anyway, you may not need to use them and instead just update to the newest version of bitcoin core - from:
https://bitcoin.org/en/download.
It is suggested you use some sort of "cold storage" like a paper wallet whcih can be made from your bitcoin-qt.exe software.
You have three different bitcoin addresses because there have been two (or more) transactions done into your wallet.
If each of those addresses have only had few transactions, at the cost of ~0.002
BTC you could always import your "private keys" into an electrum wallet then you don't have to wait for it to syncronise.
(NOTE: you may need to resynchronise with the network once you have upgraded the software.