If it is a wallet from 2015, you surely had Legacy addresses because Segwit was activated in 2017.

With Electrum wallet, in its newest versions, the wallet software by default settings will give users Segwit addresses.

If you want to have Legacy addresses, you can import your wallet seed, and choose BIP39. You can type the mnemonic seed, choose BIP39 to try. If it accepts, you will have three options to import, as written in this guide, Restoring your standard wallet from seed.

Three are three options, you can try them and see with different wallets, Legacy, Segwit, Native Segwit, whether you have bitcoin in wallet balance.