I'm very confused with this and I would really apreciate if someone can help me with this question.
The reason for your confusion has arisen because you've started using Bitcoin whilst fundamentally misunderstanding how it works. A wallet does not *hold* any Bitcoin. In its essence, a wallet is just a collection of keypairs. However, not all wallet providers give you access to these keys which is why a wallet with full control is needed for this split.
Additionally, it is still not certain whether the split is going to be significant at all to even matter (thus all this fear and *procedures* may be completely irrelevant). It is not recommended to transact at all until the dust settles. If you are using Bitcoin Core, you can export your private keys using the debug console. If you want to use *fork coins* (if it comes to one), then you just need to download a wallet compatible with the fork and import the private keys there.
At the same address?
So, tl;dr: Yes. Same address and the corresponding private key. You just need to download a wallet that is compatible with the fork. Although, I am almost certain that BIP 148 is not significant enough for a noticeable fork.
