If you were a British scientist and/or living in the 1890s, we'd rate this book a 3 or so. But since we're guessing that you're neither, then this book is going to offer some challenges.
Some of the scientific concepts here may be difficult – so, for instance, if you need a refresher in evolution, check here. You might also find the language a little confusing. For instance, the Time Traveller is a fairly scientific guy (check out his "Character Analysis"), so he tends to use precise terms. For instance, we'd be fine calling someone who doesn't eat meat a vegetarian, but that's not good enough for the Time Traveller, who precisely notes that he was "frugivorous" while among the Eloi. (That is, he only ate fruit.) But with a little help, these problems aren't serious, and you can focus on Wells's larger points.