Well, many thanks for the good advices.
But if I want to buy bitcoin with PayPal or Credit Cards, which platform can you suggest? Safe enough and can be trusted by the buyer and seller.
The best rates you could get are probably from individuals but for PayPal you have Virwox, as for credit cards: Cex.io, Coinbase, Coinmama, BitPanda. The availability of these services depend on your location (KYC verification could be needed).
Is the transaction fee in virwox high? And does they have a maximum amount to convert? I am also interested to convert my balance.