Siman 280
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א תַּשְׁמִישׁ הַמִּטָּה מִתַּעֲנוּגֵי שַׁבָּת הוּא, לְפִיכָךְ עוֹנַת תַּלְמִידֵי חֲכָמִים הַבְּרִיאִים מִלֵּיל שַׁבָּת לְלֵיל שַׁבָּת.
1 The Laws Pertaining to Marital Intimacy on Shabbat, 2 Seifim: Marital intimacy is one of the expressions of Shabbos pleasure. Accordingly, [our Sages] determined that healthy Torah scholars, who are obligated to fulfill their conjugal duties once a week, should do so each Friday night.
ב מֻתָּר לִבְעֹל לְכַתְּחִלָּה בְּתוּלָה בְּשַׁבָּת, וְאֵין בּוֹ מִשּׁוּם חוֹבֵל וְלֹא מִשּׁוּם צַעַר לָהּ.
2 It is permitted to engage in marital intimacy with a virgin for the first time on Shabbos. There is no prohibition because of causing pain or damage on Shabbos as a result of her initial intimate experience.