People gave some suggestions and Electrum definitely got the most votes. But you need to know one thing that the safety of your bitcoins is not completely determined by any wallet but by you . Even if you own hardware wallets , if you don't know how to secure them and use them carelessly, your bitcoins will not be safe. Especially if you plan to store bitcoins on a computer that is constantly connected online. You should save up and buy yourself a hardware wallet, which I recommend you consider.