And how can I know if speakers will go below 4 ohms? Sorry for asking so many questions, Im new to this
They probably will at some point, what matters is what frequencies they do it at, how far they drop, and how long they stay there.
Speaker ratings are "nominal" or stated numbers, not gospel. They are supposed to represent something that really can't be represented very well by one number. Some speakers are hard to drive, some are easy, which has been a recurring theme here in this thread.
I know it's a crappy answer, but the answer is always "it depends." It depends because all amplifier testing is done with purely resistive loading, not real dynamic speaker loads. "It depends" because speaker manufacturers do the same "ballparking" and some of those loads can be really wicked at times. An example from 25 years ago was the Infinity Kappa 9. Infinity rated it at 4 ohms but it had a dip to just over 1 ohm and other nasties. In short, it was a pig to drive. I walked into a hifi shop at that time where the sales crew had just smoked an Adcom 555 amp at very modest volumes due to the incredibly difficult load. The step down models were not particularly difficult, but did reward a stiff amplifier.
Best to avoid budget amps into "4 ohm" speakers. Most vintage stuff will be fine from midline on up, but modern stuff, not so much, especially AV receivers. A moderately difficult speaker load will leave them dead and lifeless sounding.
Then again, this is why there are sites like this with guys who can help you out.
BTW, IMHO, avoid the Carver TX stuff, in my experience they are not very good performers. I've never been too impressed with Carver amps/preamps, and that series was even less so in my experience. The dynamics that Carver did typically have just wasn't there with them. There are a ton of good amps out there to choose from.