I do ride long rides by myself at times but I prefer to go with someone else. Talk to the local bike shops and the cycling group to see if there is anyone who would be willing to ride with you. I found that there were several riders that did not ride with the main group because they too were not fast enough or not riding long enough. I have moved through several groups as I progressed but have remained good friends with all of them. I now ride with the cycling group for the majority of my rides because I have worked up to that level. Good luck!