Is Havdalah said at start of Chol Hamoed?

Yes, Havdalah is recited at the end of the first Yom Tov of Pesach and Suckot. However, because it is not the end of Shabbat the only Brachot that are recited are on the wine (Hagefen) and Hamavdil Bein Kodesh Lechol. These are the Brachot you should make: בָּרוּךְ אַתָּה ה', אֱ-לֹהֵינוּ מֶלֶךְ הָעוֹלָם, בּוֹרֵא פְּרִי הַגָּפֶן/הַגֶּפֶן. Barukh ata Adonai Eloheinu, Melekh ha'olam, bo're p'ri hagafen/hagefen. בָּרוּךְ אַתָּה ה' אֱ-לֹהֵינוּ מֶלֶךְ הָעוֹלָם, הַמַּבְדִּיל בֵּין קֹדֶשׁ לְחוֹל, בֵּין אוֹר לְחשֶׁךְ, בֵּין יִשְׂרָאֵל לָעַמִּים, בֵּין יוֹם הַשְּׁבִיעִי לְשֵׁשֶׁת יְמֵי הַמַּעֲשֶׂה: בָּרוּךְ אַתָּה ה', הַמַבְדִּיל בֵּין קֹדֶשׁ לְחוֹל: Barukh ata Adonai Eloheinu, melekh ha'olam, ha'mavdil bein kodesh l'hol, bein or l'hoshekh, bein yisra'el la'amim, bein yom ha'sh'vi'i l'sheshet y'mei ha'ma'a'se. Barukh ata Adonai, ha'mavdil bein kodesh l'hol. Chag Sameach