Regarding the game speed, that is a bug, or rather the game runs way too fast on modern processors. Fortunately, you can fix it quite easily with a fan-made patch. Check out this thread: http://www.gog.com/en/forum/might_and_magic_series/mm1_read_this_if_you_think_the_text_appears_too_fast/page1
The newest verison of DOSBox also helps with speed issues, but the fan-made fix is the best fix in my opinion. I actually forget if it affects the intro screen but it definitely affects in-game text (with a few very minor exceptions... like if an enemy skips its turn in combat, that still goes past very fast). Only MM1 suffers from such speed issues, all the rest work fine.
Starting with MM1 is totally fine. Just remember that it is the oldest (from 1986!) and the series improves a lot in terms of technology and ease of interface and such. So if you find that MM1 is too hard / too oldschool to deal with, don't give up on the whole series, try some of the later games (like MM3 for example).
I recommend drawing your own maps, as it's fun and lets you note down special locations. But there are also plenty of maps available online. There's also maps in the cluebook that you get with the GOG pack. If you haven't grabbed the cluebook, it's under the "additional content" menu when you click on the MM pack on your GOG account page. The cluebook is also useful for identifying items... otherwise it's very hard to discover which weapons and armor are best. I used it for items only but drew all my own maps. The key thing to realize when drawing maps is that every area is a 16x16 grid, numbered form 0-15 in x and y. If you cast the level 1 sorcerer spell "location", it will tell you where you are on this grid (x,y coords) and the direction you are facing. That tells you where to start drawing your map. After that it's pretty easy, and you can always double-check with the location spell every now and then to make sure you've done it right. Use a pencil!
Oh, and yes, the game starts without any story really. You need to explore to learn what's happening in the game, but even so it's not very story-heavy. Most of the gameplay involves exploring and slowly piecing together what the main quest is about. There are many hints in the first town about special things to do and places to look for also.