I occasionally play on lichess - all levels play there and free mobile app and web. I recommend playing humans instead of computers as you experience the full human range of possible ideas.
When humans battle, each side is giving 100% to crush the other side. Today your mobile chess app will crush every grandmaster on earth so programs have to handicapped in order for a human to win. So even when you win, you have just won against an opponent that gave 10% and I just don’t find that very satisfying. Nothing beats the battle of two human brains IMO. Not to say computer analysis is not useful, just saying I prefer battling humans.
