I would turn down some settings in the dsfix config. For example AA, AO and DOF. DSfix can be really taxing with some of the settings, your gpu/cpu won't be able to handle them.
Are you playing with a keyboard/mouse? If yes, make sure to also download
dsmfix. Plop the dsmfix files into your DS directory then open up DSfix and change this line:
dinput8dllWrapper none
to:
dinput8dllWrapper dsmfix.dll
Also for dsfix to work you need to TURN OFF in-game AA with the in-game settings.
As for builds shield/sword is a good way to go. Blocking gives you a lot of room to survive against some of the harder bosses as you learn to roll. If you want to use a little bit of magic try throwing in some Faith. So you would be VIT/END/STR/FTH. That way you can use a few offensive spells and healing. Otherwise full END/VIT/STR will be very durable. For weapons I would use a Longsword for its great moveset and the Grass Crest Shield when starting out for the stamina regen (you can Google where to find it, it's available VERY early in the game so a guide really wouldn't have any significant spoilers).
Edit: Sorry I forgot to mention that the offensive faith spells will require you to be a
Sunbro but who doesn't want to be a Sunbro?