Both Twitter and IG are very useful. It will depend on several factors for you:
1) If your primary goal is networking with female community members, having access to information quickly in real time as it pertains to the community, access to the branding and marketing knowledge of ladies world-wide and suitors world-wide then go with Twitter.
2) If you wish to generate a male following relatively quickly (this will depend on the content you produce and how adept you are at #1) that have the strong possibility of becoming your suitors go with Twitter. For some ladies, up to 30% of their suitors are from Twitter.
3) If you create visuals that are engaging and interesting and wish to be photo-centric, wish to create and curate a more "intimate" following, be targeted to certain categories and hashtags more assuredly, decrease the risk of shadow banning then IG.
WARNINGS
In the wake of new legislation, Twitter will shut down ladies accounts. Since you are new to twitter, you will the opportunity to start fresh and create your account in a way that doesn´t violate Twitter´s new terms and conditions of usage. Twitter is still shadow banning accounts based on certain words and hashtags used in posts. IG is owned by Facebook. Before getting on EITHER platform, I would suggest curating all your personal social media accounts first. Facebook´s and Google´s bots are quite adept at linking and matching profile across social media. As someone who monthly sends out DMCA takedown notices to scraper sites and regularly has my copied ads and images removed understand that you (almost) have no recourse when it comes to social media as your posts are in a way viewed as "community property" especially on non-private accounts in IG and Twitter (I am assuming you would have your profiles set to public where anyone can follow you and see/access your photos).
Off the top, these things are what come to mind. Feel free to email me if you would like to chat in greater detail.
Olivia Corvisart