Slicer: orcaslicer. It’s a fork of Bambustudio, which in it’s turn is a fork of PrusaSlicer, which if my memory serves me right is a fork of Slic3r, which was open source, so all of the mentioned slicers are free
i use orca as it has a few nice upgrades/improvements over bambu, and since i’m running a bambulab printer…
It does support other brands of printers too.
As for filament dryer:
Do you have a multi material printer? Like, does it change filament when printing? Or is it single filament?
For multi you’d have to look to a dryer that can dry and possible feed multiple rolls. If it’s a single filament printer, you can do with a cheap (relatively cheap) box, like from sunlu, esun , creality or whatever. I’m running an Eibos box, but i actually seldom use it, mostly for when i print difficult materials that are easily affected by moisture (tpu, pva, …)
You could also use a food dehydrator, they’re usually cheaper and can hold more rolls.
Some honourable mentions:
Put it on the hotbed with a cardboard box over it, instant dryer solution.
Use the oven in the kitchen, but beware, there are some funny stories in the wild about this method
You can find a dryer anywhere between maybe $30 to a couple 100’s