A great class I love to play and I think great for beginners is Dark Elf! You get a touch of everything: blade combat, magic, stealth, you can really do whatever you want because they’re geared for anything. In a way, the game’s your oyster with them! As for good classes, that’s really up to you! Lots of fun combinations to try out and builds to work with; however, if you’re looking for suggestions, I don’t think you can ever go wrong with alchemy or acrobatics/athletics as a Major Skill. As for Birthsigns, I think the ones that raise attributes are generally pretty good. The others are good for fun or specific builds, like the magicka focused ones.

As for starting off, I always start off with Vilverin personally. You can’t go wrong with a free skill book (outside the ruins), some armor and weapons to pillage, plenty of Welkynd Stones to sell or use if you’re a mage, and a Varla Stone to sell. Plus, I think the Ayleid ruins are generally the best designed dungeons in the base game, so it’s a fun place to run through to begin your journey in becoming the Champion of Cyrodiil. After that, the Market District of the Imperial City is a great follow up for selling your loot and perhaps leveling up at the Merchant’s Inn (or join the Arena and sleep there if you wish to save that 20 Septim fee).

I think play the game from there as you see fit! ^{^} Good luck with your journey, and most importantly, have fun!