Before you can deploy a contract or send a transaction, your wallet needs KLV (or testnet KLV) to pay gas.
Testnet
Testnet KLV is free. The official testnet faucet hands out a small amount per request. Search "Klever testnet faucet" and use the official link from klever.org. You may need to wait between requests.
Mainnet
Mainnet KLV is bought on a centralised exchange or received as a transfer from another wallet. Buy a small amount the first time. Expect a small fee on each end.
Always send yourself a tiny test transaction from the source first to confirm the address is right. A typo on a sixty-character address is permanent.