You know, ignoring the fact that is DOES seem really hard for people to avoid running afoul of antisemitism, it really shouldn't be.
Here's a list of legitimate complaints I have against Israel:
1.) There was undeniable ethnic cleansing in 1947-8. The strongest argument the pro-Israel side has against this is simply that not every one of the 700,000 people who identify as the Naqba population were actual forced out of their homes...they just ran in fear instead (for a variety of reasons that we shouldn't get into obviously). I think it is quite clear that incidents like Deir Yassin and Al Dawayima amount to blatant ethnic cleansing and events like the exodus at Lydde and Ramle were clear population transfers.
2.) Israel discriminates against Jews. Ask a Mizrahi or Beta/Ethiopian Jew how they are treated in Israel and you'll get a stark difference in picture compared with what an Ashkenazi (like myself) would tell you. One of the most striking features of this inter-Jewish racism (that exists mostly on color lines but not entirely) is how the Arab/Mizrahi Jews expelled from Arab countries between 1948 and the early 70s were actually treated in Israel. Concentration camps, forced sterilization, immense squalor and poverty, restrictions on movement, etc. This was a very dark mark on Israeli history, but most pro-Israeli people are happy to tout the diversity of Israel as if it were some feather in the hat of Israel being awesome.
3.) [this is true for both sides] - Israel has a history of negotiating in bad faith. Just a couple of months ago came Israel's latest round of negotiation offers. It's no surprise that they offered them now, when Palestinian fervor has reached a point where it's on the verge of a 3rd intifada. The conservative iteration of the Israeli government is not interested in peace but because they know the rest of the world is, they offer token gestures like this most recent one. Of course Abbas wasn't going to accept, it would have been political suicide. Israel knew this, expected it, and managed to twist reality so as to show Palestine as being the anti-peace party.
There are many more, but you should get the picture by now that I do believe that there are indeed ample and legitimate criticisms of Israel. That said, the antisemitism that I find all too frequently isn't necessarily in the core of the criticisms themselves but rather in the presentation of those speaking it. This point is going to be highly controversial if you're not a Jew, but I am very wary of any Western/European criticism on Israel solely on the grounds that neither society has taken anything but the most nominal steps to address its own anti-Jewish past and present. For a young non-Jewish American today, it is almost expected for them to be ignorant of all Jewish experience except the Holocaust. They have no idea the history of accusations about disloyalty (long before Israel ever existed), the barring of Jews from public institutions, the racially restrictive covenants that kept Jews from being land up until the mid-20th c. (!), and many more events that are by no means ancient history.
So by all means criticize Israel. Just make damn sure you know what you're doing.