Like anything you do, you should count the cost before you commit to something. You should know what to expect if you become a Christian. It isn't always easy. The Lord calls us to integrity, honesty, faithfulness, truthfulness, etc. In a world of moral relativism, such absolute qualities do not fit well. It can cost you.
Also, if you become a Christian and then continue to live in sinful ways, the Holy Spirit will gently and convincingly prod your heart and bring you to a place of repentance. He is persistent. He won't give up, and sometimes that repentance can be difficult, especially if He brings you to confess your sins to others and make things right.
You must understand that if you become a Christian you are no longer your own. You have given yourself to the Lord, and He takes that commitment very seriously. He will not leave you in your sins. He will work in you and gradually bring you to a new place in your life. He will work bad habits and bad things out of you over the rest of your life. Of course, this does not mean that you will become perfect. It means that God will work in your heart to make you more like Jesus. You can expect this because God is living in the heart of all who have received Christ (John 1:12, 14:23). This is because Christians experience the very presence of God and God is holy.
Being saved is easy. You just trust in what the Lord Christ has done, receive Him as Savior, ask Him to forgive you of your sins, and trust in nothing else (including your own "good works") for your place in Heaven. Getting saved is easy. The hard part is what follows after you become a Christian when the Lord comes to live in you and then begins to work change in you--for the better. Sometimes it is quite difficult, but other times it is very rewarding.
God will accept you just as you are, but He will not leave you as you are.
So, if you want to become a Christian, expect your life to change. Expect that you will end up with different friends and be prepared to find that many of your old habits and desires will also change. This is what you can expect, but it is worth it.
One last thing
There is one final expectation that you should be aware of if you become a Christian: salvation. In other words, you'll escape the righteous judgment of God. Eternal Hell is what awaits those who fail to trust in what Christ has done on the cross. Being a Christian means that you have escaped that judgment. This, of course, is the greatest benefit for you.