Thanks for all the advice!

I love snowboarding. It's definitely something that I will be doing for years to come so I want a board that'll at least last the next two seasons.
The board I'm renting for the season is a Rossignoli Accelerator Bmp, 150cm snowboard, burton boots and bindings. My boots are a little too big for me too but they had no other size. The person at rentals said the rentals are around 6 years old. Super beat up… anything would be better then what I'm riding right now. I just rented because I wanted to try it out first and it was pretty cheap.
I don't know how much of a beginner I still am. I go on blue runs and I just started doing jumps. I'm landing them too! Of course they're not big jumps, but still, it's exciting for me.

I'm still working on going fast because it freaks me out. So a softer board would definitely be a good idea. How soft should I go? And what size do you recommend?
The snow conditions are okay? I don't really know how to answer that… snows every now and then. I'm told the snow is usually packed and icy. I definitely need something with a better edge hold.
So K2 and Burton are some brands I should look at… any other brands/boards you recommend?