When talking about hiking SugarLoaf up you need to understand that there are two hills that are part of the Sugar Loaf complex:
Sugar Loaf: 396 meters (1,306 feet) above sea level, which you can hike up most of the way through the forest, but at some point you will need to climb the rock to get to the summit of Sugar Loaf.
If you are a beginner, you should hire a guide to take you to the easiest path up to Sugar Loaf, called Costão. Climbing gear will be necessary and your guide will provide that. There are other paths for experienced climbers, with less walk in the forest and more rock-climbing experience.
Urca Hill: 220 meters (726 feet) above sea level. If you only want to hike and not to climb, then you cannot reach the summit of Sugar Loaf by hiking only. However, you can hike the trail up to Urca Hill, which is the hill half way to Sugar Loaf. A cable car connects Praia Vermelha (Red Beach) at sea level to Urca Hill, and then another cable car connects Urca Hill to Sugar Loaf. So, if you want to do some hiking you can skip the first cable car, hike the trail up to Urca Hill, and then take the second cable car that will take you to Sugar Loaf.
You don’t need a guide to guide you through the forest up to Urca Hill, but a map will help. Get a copy of Sugar Loaf: The Defintive Guidebook and have instant access to maps of the area that will help you to hike up Urca Hill on your own.