Welcome to SRP. There are some great deals on str8s in the classifieds. I assume you have a brush and soap, but do you have a strop?

I've never shaved with a disposable str8, but I've read here that they are less forgiving than regular str8s.

I've read about the 30 degree angle and also that the spine should be 2 spine-widths off your cheek. I'd guess that my blade angle is more in the 15-20 degree range.

Enjoy your shaves.

Dave