Many agents have questions regarding the merits of maintaining multiple websites and domains. Here is some information to help with that decision:
Every website you have, whether it be one or more, should have a custom domain as primary. Domains such as "myname.engageREagent.com" may be convenient, but not too useful from a marketing or SEO perspective. In that example, this is a "default" domain created automatically for your engageRE account, and can be used, but we suggest assigning a custom domain.
You can have multiple domain names point to the same website if that serves a specific marketing purpose for you. In general, those secondary domains do not accrue SEO value, and may dilute or confuse your identity and messaging, but technically there is nothing wrong with using them.
Likewise, using multiple websites is really a personal business preference. They can help you tailor your messaging to a specific audience or market. You can experiment with different promotions and advertising easily. Note that there is some overhead in maintaining multiple sites (and multiple back ends) that you should weigh. One big disadvantage is that you will be splitting your SEO and marketing efforts between multiple sites.