GreenTengu
Adventurer
This is done a lot easier by just using a Paladin and gaining proficiency in Stealth and thieves' tools through your background.
Maybe I should have explained why then...
Those three classes will give you proficiency bonus in all saving throws. The importance of this cannot be overstated given that every ability on every monster will be thrown at you and if any of the things you fail leave you stunned, entangled, asleep, charmed, etc.... you are dead. Instantly, right there, on the spot you are dead. There are no other party members to wake you up or heal you or keep the monster from getting close to you.
The monster just walks up and coup de graces you. It is as simple as that. Every single ability that would normally simply be "take a PC out of combat to focus on the rest of the group" becomes a "save or die" spell when you are solo. You need your save. You need ALL your saves.
Now, the Cleric level gives you the ability to restore your hit points. Maybe not a huge amount, but enough to keep you alive and going.
The Rogue level gives you the ability to deal an extra 1d6 damage whenever you can get advantage. Stealth and Deception give you ways of getting advantage. It also gives you the requisite Thieves Tools giving you the ability to get past various locked doors and traps.
Straight Paladin doesn't get you any of that. You need to take Fighter/Cleric/Rogue to be able to achieve this. You can start with whichever piece you like, but you should have 1 level in each at level 3 and you'll be the best rounded level 3 you can be. You won't be nearly as good as a specialized class, but you won't have any giant glaring weaknesses to be exploited like most classes...
Well... there is one....
Anyone with a net can kill you and you won't be able to do much of anything about it. But that is going to be true if you play anything but a strength-based character.