As mentioned by James Rawlings in the comments, it's likely to be a resource issue. The recommendations in the manual are:

A known good configuration on a 2015 model Macbook Pro is to use 8 GB of RAM, 8 cores, a 150 GB disk size and hyperkit.

The disk size is particularly large as a number of images will need to be downloaded.

So we highly recommend using one of the public clouds above to try out Jenkins X. They all have free tiers so it should not cost you any significant cash and it’ll give you a chance to try out the cloud.

Default minikube installation uses only 2048 MB of RAM, 2 CPU cores and 20Gb disk space. You can adjust minikube VM size using command line options:

$ minikube start --cpus=8 --memory=8192 --disk-size=150g --vm-driver=hyperkit

or use jx tool for that:

For MacOS

$ brew install docker-machine-driver-hyperkit

# docker-machine-driver-hyperkit need root owner and uid 
$ sudo chown root:wheel /usr/local/opt/docker-machine-driver-hyperkit/bin/docker-machine-driver-hyperkit
$ sudo chmod u+s /usr/local/opt/docker-machine-driver-hyperkit/bin/docker-machine-driver-hyperkit

$ brew tap jenkins-x/jx
$ brew install jx

$ jx create cluster minikube

For linux:

$ curl -L https://github.com/jenkins-x/jx/releases/download/v1.3.784/jx-linux-amd64.tar.gz | tar xzv 
$ sudo mv jx /usr/local/bin

$ jx create cluster minikube