The Shabbat is a time concept unknown to non-Jews. Travelling to Israel gives you the need to coordinate your travel plans in or around this time slot. It starts at sundown on Friday (often with a dinner of the family) and ends on Saturday at sundown. During this time shops are often closed, you might not check in to hotels (though I never experienced this problem) and most major sights are shut down. Just like on Sundays in Germany, only from dusk till dusk.
Official currency of Israel is the New Israeli Shekel (NIS), divided into 100 agorod. The sign used to display shekel values is ₪. Banknotes of 20, 50, 100 and 200 shekels are circulating; you get coins of 10, 5, 2, 1 and 1/2 shekel value. You could exchange money in your home country, but it is most often recommended to bring EUR or USD – you can easily exchange these currencies against NIS at post offices (even as there might be some waiting lines).
The Hotel Melody in Tel Aviv-Yafo, Israel is a wonderful boutique hotel close to the Mediterranean Sea and the old harbour of Tel Aviv. It is in second row to the sea, half behind the Hilton Hotel and the Independence Park. A walk to the waterline lasts only five minutes, also a walk to Ben Gurion street for shopping or having a coffee is the same distance away.
The Ben Gurion airport close to Tel Aviv-Yafo is a very modern and good airport of medium size. It is connected by train to the city but most travellers might prefer rental cars instead. Arriving at TLV starts with a passport control that can last some minutes and includes some trivial questions about the planned stay.