I've largely taught myself. At first just stick to very basic things like wipes, square things like tea-towels, flat sheets, pillow cases. Then progress to shaped but flat things like aprons. I wouldn't attempt to use a pattern until you feel confident doing these basic things.
Get the hang of changing the tension according to different types of fabric. Learn the difference of sewing stretchy and non stretchy fabric (stretchy can be much more tricky). Get the hang of sewing curves and snipping the fabric so that it curves nicely (like you do with baking paper for a round cake tin etc).
Learn how to put a zipper in. Make a basic pencil case and pop in a zip.
Learn how to do a button hole.
Depending on whether you know all this basic stuff I wouldn't attempt a pattern yet. But if you do and want to have a go at using a pattern then some are easier to read than others. Ask the shop assistant which is a easy brand. Simplicity brand are ok... choose patterns that have the "facile" rating (French for easy).
What have you made in the past? Other than wipes?
Remember that if your machine doesn't have an overlocking function that you will have to either learn how to do French seams (to stop fraying) or just be content with using pinking shears to slow the fraying. I don't have an overlocker and have been put off making clothes now because I'm fussy. But I have saved lots of money making basic things that are easily hemmed like curtains and aprons.
I'm far from being an expert sewer though... have learnt by trial and error. My mother is an excellent sewer and makes us lots of clothes as she has an overlocker.
ETA: also buy an unpicker! A vital little piece of equipment that helps you easily unpick mistakes.