Starting small is actually a very smart strategy to test the waters before diving in deep. You definitely want to avoid bank transfers for small amounts because they are slow and banks might flag the transaction. If you have access to it, using systems like BLIK or even certain cryptocurrencies like Litecoin is the way to go because the limits are usually very low. For example, on the
official site Mostbet, you can see that they allow really flexible minimums for these methods. I personally use Mostbet because they do not charge any commission on deposits, which means if you send 50, you play with 50. It really annoys me when casinos take a percentage, but these guys keep it at 0% for almost every method including crypto. Just make sure you check if the method you choose for deposit is also available for withdrawal later to keep things simple.