You mention sci-fi, which is right up my alley.

Recently finished up Enders Saga, which are not at all difficult books to keep up with, and very, very good. Give Ender’s Game a go if you haven’t already read it. If you like it, there are A LOT more books in the series.

The Final Architecture is Adrian Tchaikovsky’s most recent trilogy, and now that it has all three books out, you won’t have to wait in-between reading them like I did. Also has a story that’s interesting, but not difficult to follow like some of Tchaikovsky’s other books.

For something really easy, try the Murderbot Diaries. They are short, but there’s a lot of entries in the series. It’s about a security robot that gains its freedom by hacking its governor module, and hence could go on a human murdering spree, but it doesn’t really feel like doing it. Too much work.

For something more involved, look at Alastair Reynolds Revelation space series, or to keep it simple read his standalone book “House of Suns” a huge favourite of mine.