:salam2: Sister,
Before I begin with the answer I would like to tell you that there will always be people who would question everything. If there wont be The Kaabah they might be asking you about bowing to the earth
There are major differences between the two.
1. We do not worship the Kaabah neither believe it to be a deity nor an avatar nor that it is divine while the idol worshipers believe there idols to be deities or avatars of deities or divine.
2. We do not ask Kaabah for anything. The idol worshipers ask from their idols.
3. We believe it to be a creation separate from the Creator and we do not worship any creation.
4. We do not believe that Kaabah represents Allah or is a replica of Him.
Allah says in the Quran, and this is the clear proof from the Quran itself.
And (remember) when We showed Ibrâhim (Abraham) the site of the (Sacred) House (the Ka'bah at Makkah) (saying): "Associate not anything (in worship) with Me, [Lâ ilâha ill-allâh (none has the right to be worshipped but Allâh), and sanctify My House for those who circumambulate it, and those who stand up (for prayer), and those who bow (submit themselves with humility and obedience to Allâh), and make prostration (in prayer);" (26)
So even when Ibrahim (PBUH) was only shown the place to built the Kaabah the message that "
"Associate not anything (in worship) with Me, [Lâ ilâha ill-allâh (none has the right to be worshipped but Allâh), and sanctify My House" was given and stressed upon so there remain no doubts as to what Kaabah is.
At the time of the Prophet, people even stood on the Kaabah and gave the ‘adhaan’ or the call to prayer. One may ask those who allege that Muslims worship the Kaaba; which idol worshiper stands on the idol he worships?
We simply face towards it during the Salah as Allah has ordained us to do.
Verily! We have seen the turning of your (Muhammad's SAW) face towards the heaven. Surely, We shall turn you to a Qiblah (prayer direction) that shall please you, so turn your face in the direction of Al-Masjid- Al-Harâm (at Makkah). And wheresoever you people are, turn your faces (in prayer) in that direction. Certainly, the people who were given the Scriptures (i.e. Jews and the Christians) know well that, that (your turning towards the direction of the Ka'bah at Makkah in prayers) is the truth from their Lord. And Allâh is not unaware of what they do. (144)
Regarding the black stone, hajr-e-aswad, there is a hadith (tradition), attributed to the illustrious companion of the Prophet Muhammed (pbuh), Umar (may Allah be pleased with him).
According to Sahih Bukhari, Volume 2, book of Hajj, chapter 56, H.No. 675. Umar (may Allah be pleased with him) said,
"I know that you are a stone and can neither benefit nor harm. Had I not seen the Prophet (pbuh) touching (and kissing) you, I would never have touched (and kissed) you".