A few tips I think are good for first timers:
Start slow. Do the reading, and then post any questions you develop.
Start slow. When you make your first purchase, don't pile up on labware and flavors. You can get started with a couple of disposable syringes, some empty bottles from premade
juice, and some VG and/or PG. Nicotine base if you will use nicotine and a few flavorings will round it out.
Start slow. Make your first mix a small batch of unflavored, and vape some of it. You may like it (I do), but even if not, that allows you to check the quality and flavor of those ingredients.
Start slow. Do single flavor mixes of each flavor before combining them. Start at a low percentage and work your way up. Many vendors provide recommended % ranges, and for others you can post a question here.
[edit]Also, download one or more of the calculator applications and practice with some imaginary recipes. That may generate some more questions you will want to have answered before your first mix.