The phrase "enter up on" can be replaced with several synonyms, depending on the context. For instance, if someone wants to talk about registering for a new account, they could use the phrase "sign up for" or "create." For a more formal tone, "enroll in" or "join" may be appropriate. If entering a building or facility, "go in" and "step inside" could be used. Similarly, "access" can be used when discussing technology or online platforms. It's important to choose the appropriate synonym for the context and audience to ensure clear and effective communication.