I'm planning to pump this weekend for the occasional bottle - how do I ensure my supply doesn't suffer?

Looking for some advice and tips here!

I'm a FTM to a 5.5 week old son. I exclusively breast feed at the moment, feeding on demand. Which is exhausting. Truthfully, I kinda hate it.

I've finally managed to convince my husband to introduce a bottle to our son at 6 weeks which is on Saturday for the OCCASIONAL feed. We've agreed I'll still EBF but that I can pump and store some bags in the freezer for occasions where I cant be (or dont want to be) on feeding call for LO.

I've bought a manual pump from Lanisoh as it says their manual pump is good for occasional use.

But I'm worried about my supply. I've heard when you breastfeed and pump, it can give you an over supply. Currently my LO feeds on demand, and when he cluster feeds he can go from boob to boob for hours. Is there anything I should be doing if I'm planning to pump now and again? How can I ensure it doesnt affect my supply?