There are some startups that announce the funding as soon as they get it, others save the announcement until they are ready to raise more.
While there is no “right” strategy, you should take into consideration the timing of your funding announcement. Funding begets more investors being interested. Announcing it right away, while seemingly sounds like a great idea, can keep you away from focusing on the product and business (this is if you entertain those investors).
While at the same time, by not announcing it, things like getting users (while not directly related), hiring the best talent, as well as a few other things may be delayed. You also run the risk of someone breaking the news and losing control of the message.
Whatever you decide, raising money (and announcing it publicly) is just the beginning of the journey. It’s funny because fund-raising ends up to be one of the easier parts of the startup process. Building a great product, scaling a business- now those are the hard parts!