I'm thankful for your interest in the Bible - and I hope you won't let minor questions like this distract you from its main message. Even if some things in the Bible remain unclear to you, its central message is absolutely clear - and has the power to change your life. Don't overlook it!
What is that message? It is the message that God loves us, and has demonstrated His love for us by sending Jesus Christ into the world for our salvation. The Bible says, "This is how God showed his love among us: He sent his one and only Son into the world that we might live through him" (1 John 4:9). We are separated from God because of our sins, but God wants to erase our sins and make us part of His family forever - and this is possible because Jesus Christ died for us.
During His ministry, Jesus healed many who came to Him - and you are right: Sometimes He warned them not to tell others about it (although they often did anyway - see Mark 7:36). Why was this? One reason is because He feared that people would only focus on His miracles, and overlook His real reason for coming into the world - to save us from our sins.
Make the Bible part of your life every day - but most of all, make Christ part of your life every day. By a simple act of faith invite Him to come into your life today - and He will.