@Chessy68 Welcome to GMRS. As far as antennas go, Both Nagoya and Abbree make a 771G which is a very good antenna. Nagoya also makes a 701G which is shorter but still typically better than the stock antenna. Abbree doesn't offer the 701G yet, only the 701UV. Abbree does provide some good Tactical antennas. I haven't tried one yet but so far all the reviews I've seen have been good.
I live in Baytown. I'm not aware of any GMRS clubs in the area but there are a lot of good repeaters around here. Check this site, myGMRS.com and also texasGMRS.net to find lots of good repeaters.