You can reach such subscriber goals with following the below-mentioned strategies:
You must create some high-quality content that brings engagement.
You must leverage free social media platforms.
Must Collaborate or join podcasts
Utilize email marketing campaigns to keep in touch with existing subscribers and encourage them to share your content with others.
Use paid promotion or advertisement to reach a new audience and drive them to your channel.
Optimize your channel and videos for discoverability by using relevant keywords and tags.
Host a giveaway or run a promotion that incentivizes people to subscribe.
Be consistent with your posting schedule, and try to post new content regularly.
However, Keep in mind that building a subscriber base takes time and consistent effort. It's also important to have realistic expectations.