questions about bjs and sex

okay so I'm new to the whole sex stuff and haven't really experienced much I lost my virginity to my fiance and we've been together for 2 years and I haven't given him a bj is or was anyone else scared for the first time that their guy wasn't going to feel pleased? My fiance has had partners and his fix with girls before me... we have a 5 year difference and I want to do more stuff in the bedroom but I just feel like I'm not as good as what he's had any advice?