Since my period returned postpartum it has been very irregular. Do I need to wait for it to regulate itself before trying to concieve?

No but less fertile. No. Are you just a few months post-baby? I assume you're done breastfeeding. You can try, but it may take longer to conceive because you're not ovulating regularly. Causes include polycystic ovarian sydrome (pcos), thyroid or prolactin hormone issues, aging of the ovary, or low hormone levels from exercise, eating disorders, or stress. See reproductive endocrinologist or ob/gyn if you're concerned.
It depends. Whether u should wait 4 your cycles to regulate on its own depends on how far postpartum u are. In the immediate pp period, the cycles may be irregular & that's normal. It is generally recommended that u wait at least a year b4 trying 2 conceive anyway (if you just delivered a baby). Studies show that spacing your pregnancies improve outcomes. If it has been a long time, u should see your md.