Playing solo for the first 150 levels or so will need a mixture of play styles, so don't worry too much to start with. You'll be getting scrolls to reset your stats and skills at around level 43, which you can hold on to until you actually need them. Most players will do a complete re-think of the character when you reach CP 160 and can start to use "end-game" gear. That's when you specialise as a Tank, Healer or DPS, and re-allocate everything accordingly.

The only thing you can't change later is class, but that doesn't completely determine play-style. Sorcerors will find it easiest to do the DPS role, and Dragonknights the Tank role, but yours may go other routes. All classes get magicka-based skills (with a few stamina morphs) and most weapons develop stamina-based skills (except staves), so the magicka/stamina choice boils down to using class skills versus weapon ones. Use them all while you build, and you'll have more options later.

Another point to note is that most XP is allotted at the end of quests, and what's on the active skill bar at that point determines what advances. So you can raise a skill you hardly ever use, just by slotting it, and swapping bars at the right time. If you also make sure the bars contain a mix of your class skills, they'll all go up, and you can get all the passives you want.

Join the Fighters and Mages Guilds, and the Undaunted, so you can start raising their skills. Thieves, and Dark Brotherhood, too, if they appeal. Psijic level one is useful, even if you don't take it further.

There are a number of things that take a lot of time for everyone. Crafting research, mount training, Undaunted and other guild dailies, are all on timers that stop you going any faster. So start early if you intend to finish.