Olaf the Stout
Hero
I totally agree with the others who basically toss party optimization out the window. Nobody should ever feel forced to play any particular class. 5e is versatile enough to have very strange party combinations and still work. I like what others have said about making sure that the PC is tied into one or more of the others by way of background or other non-mechanical hook.
I've never had a bad time DMing a group or playing in a group when everyone played what he/she really wanted to play. Enthusiasm for a character concept far outweighs optimization as a party.
One thing you can do is talk with the other players to to see if any of them want to build their character concept along with your character so that you can decide how you might interact together during the campaign. Even when there are multiple rogues or multiple fighters or multiple spellcasters, often by coordinating backstories and personalities, it opens up lots of ideas for healthy inner party competition or bonding/support in other ways.
That said, there are also many players out there who don't mind choosing what the party needs to make it more well-rounded, and those players like the challenge of creating that piece of the puzzle that seems to fit well. If you are that type of player, I'd think about playing a fighter, barbarian or paladin.
I know that 5E allow for more options when putting together a party as there isn't as big a need to have a Cleric in the party (due to Short and Long Rests).
That said, having a Cleric in the party definitely makes life a lot easier and the group as a whole much more effective in combat. Our party does not currently have a Cleric and we've found the lack of healing to be tough. Once someone goes down in a fight they're now out of the fight and the best you can do is stop them from dying.
We're currently playing LMoP. Last session our party got ambushed coming out of a shop by the Red Brands gang. In the first round of combat 2 out of 5 PCs were taken out before we could even act. Thankfully the 3 remaining PCs took out some Red Brands allowing both groups to end the fight without anyone dying, but had it been a fight against a non-intelligent monster it could easily have been a TPK.