I've used a few sites to acquire a small amount of Bitcoin to play with. These sites give you some and seem to pay for themselves using advertising. If you have an ad blocker they don't generally work.

Bitcoin Zebra- you can play every hour to get a random amount. Can be 2000 satoshi at the moment

Moon Bitcoin - accumulating amount. You can claim every 15 minutes. The rate drops over time if you don't claim.

With both of these if you have a wallet at Xapo you get a bonus (25% at the moment).

It's easy to do these at intervals if you are on-line anyway. You can set a timer to remind yourself or the sites can do this themselves if you allow it.