I have been on my own for 4 years now and have ventured into online dating cautiously and with a degree of anxiety about this but have now dippedy toe in the water and it's not do bad if you can handle the expected norms of behaviour. It is definitely not the same as when dating when young.
I like Apricity' comment about avoiding seekers of the nurse or the purse! The S rules also are a good starting point. Sense of humour,
Shared Interests, Sexual compatibility, Solvent, Sane, Schooling & Social Standing, and also possibly the Speed of the relationship. Go at your own speed and don't be pressurised or pressurise your date. Show your natural personality.
While many of us have the fall out of past relationships to deal with, it's best to avoid heavy baggage carriers and being a baggage handler. If after a while you think you will be uncomfortable introducing Mr X to your friends and family, heed the warning inside your head.
Dating should be fun but I think it is important to establish discreetly what both sides may be seeking in the longer term, particularly once you reach a certain age, you don't want to either be or be subject to time wasters. If you get to the stage when you are not enjoying looking forward to seeing someone, then it is probably time to call time and move on. If on the other hand the relationship progresses further, take legal & financial advice before getting to a point of no return, especially if assets are at stake, and where these are unequal.
Good luck, proceed with a good balance of caution and excitement in your new found friend!