Here are some handy Salesforce CLI sf (v2) commands for working with scratch orgs:
Remember to Uninstall the previous sfdx CLI before installing sf.
# installation
$ npm install sf
# create a DX project
$ sf project generate -n my-project
# authorize a default DevHub
$ sf org login web -d -a default-hub
# create a default scratch org
$ sf org create scratch -f config/project-scratch-def.json -a my-scratch-org -y 30 -d
# View the list of our orgs
$ sf org list
# generate a password for the default scratch org
$ sf org generate password
# push all local metadata changes to the scratch org
$ sf project deploy start
# assign permission set to the current user
$ sf org assign permset -n My_Permission_Set_Name
# run a script (for example to create sample data)
$ sf apex run -f ./scripts/setupMyObj.apex
# open the newly created default scratch org
$ sf org open
# org details including access token, username, password, alias, etc.
$ sf org display
# deploy or retrieve specific metadata
$ sf project deploy start -d force-app/main/default/lwc/myComponent
$ sf project retrieve start -m ApexClass:MyApexClass
# set or change org alias
$ sf alias set my-scratch-org=test-dev@example.com
# change default DevHub
$ sf config set target-org=me@myhub.org
# delete a scratch org
$ sf org delete scratch -o my-scratch-org