1) You need to enable registration in the settings of WooCommerce plugin. WooCommerce > Settings > Accounts & Privacy > Account creation settings and Registration privacy policy
https://docs.woocommerce.com/document/configuring-woocommerce-settings/#accounts-and-privacy-settings
Also, watch these videos – https://youtu.be/mBp33hPMgnA https://youtu.be/eDclashcCwo
2) https://prnt.sc/xctd1l https://prnt.sc/xctedr https://www.mc4wp.com/kb/#utm_source=wp-plugin&utm_medium=mailchimp-for-wp&utm_campaign=sidebar
Feel free to ask if you have any other questions.
Regards