There are some games in online casinos which need very little skill. Things like roulette or bingo, you just have to wait and see whether your number comes up. However card games, such a poker need some skill as well as luck. It can be difficult to know which to choose.
If you are prepared to learn a game really well. Study the tactics and practice a lot before you play, then a game of skill could be better. You will need to consider that the people that you are playing against could have spent a long time studying the game and had many years of practise to get to the stage that they are. This means that if you want to beat them, then you will have to be prepared to do the same. You may be happy to do so, you may already have some skills that you would like to build on or you may have a big interest in the game, find it a lot of fun and want to play it a lot more.
On the other hand you may not be prepared to do this. You may want to start playing right away and not worry about skill. Of course there is an element of luck in all games and even the most skilled, professional poker players can lose big sums of money from time to time. You may prefer to have a more relaxed approach, not worrying about learning lots, thinking about tactics or skills but just enjoying the process of the game and seeing what luck gives you.
The choice of which type of game to play maybe to do with your personality. You may have a big desire to win and are prepared to do anything that will increase your chances of doing so. You may just enjoy the game for the fun and not worry so much about winning. You may enjoy learning new things and get obsessed by fully understanding rules and how to win or you may just not be interested. You may feel that you are more in control of whether you win, if you have to use some skills, however, it may be difficult if you realise that you could have won, had you not made a mistake. You do not have this with a less skilled game.
You could have a try at different games and see which one feels the right one for you. You may decide that you do not want the hassle of learning the game and tactics but would rather just get on a play and relax while playing and enjoy the game. You may want to be more in control and use your skills to win. It is worth thinking about which is the right fit for you.