If you've never worn contacts and you have a lot of questions about it it might be an idea to go to an optician. Besides you could maybe get some trial lenses to try on and figure out if you can wear contacts at all + vision check.
Personally I didn't use contact lenses when I started cosplaying but nowadays I use them for all my cosplays and yes, even those that share the same eye color as me. I just feel like circle lenses (contacts that make your pupil look bigger) really add the final touch to a cosplay and brings it to the next level. But yeah, if you want to wear contacts or not is ultimately up to you to decide and, whatever you choose, it doesn't make you a better or worse cosplayer. Contacts aren't neccessary but I personally think that they do make a difference.
If you're curious about my thoughts about lenses and cosplay I'd really recommend you read this post I made: "Cosplay with circle lenses – Necessary or not?"
I've also done a post with advice and a do & don't list when it comes to wearing lenses at a con etc. You can find it here: "Contact lenses – The advice and "what not to do" list!"
I hope that's helpful.
Feel free to ask me if you have any further questions!