Vim frozen and unresponsive on startup
When vim starts, it reads these two files from your home folder:

.vimrc, a configuration file that contains initialization commands
.viminfo, a history file that contains, among others, string and pattern search information

vim may become unresponsive if any of these two files are very large or contain corrupt entries.
To prevent vim from reading them, either:

Rename them:
 cd ~
 mv .vimrc .vimrc.bak
 mv .viminfo .viminfo.bak

where ~ is shorthand for your home folder.
(Ignore any No such file or directory errors, it just means the file doesn't exist.)

and start vim as usual:
 vim



or, alternatively, start vim as follows:
vim -u NONE -i NONE

where the -u NONE option tells vim not to read ~/.vimrc and -i NONE achieves the same result for ~/.viminfo.
If vim starts normally, you can rename back one file at a time to find the culprit and delete it.
If you want to find out more about the differences between .vimrc and .viminfo, see this answer. For information on the use of ~, see the Bash or Zsh manual.